Name: ______________________ Class: _________________ Date: _________ Math 10C Course Review Multiple Choice Identify the choice that best completes the statement or answers the question. ____ 1. Which referent could you use for 1 cm? a. The depth of a kitchen sink b. The length of a public swimming pool c. The width of your shortest finger d. The length of a walking stick ____ 2. Which referent could you use for 1 yd.? a. The width of your shortest finger b. The length of a screwdriver c. The height of the kitchen counter above the floor d. The length of a football field ____ 3. Which referent could you use for 1 mi.? a. The length of a salmon b. The height of a grizzly bear standing on its hind legs c. The distance equal to 4 laps on an oval running track d. The thickness of a sheet of loose-leaf paper ____ 4. Which expression represents the area of the shaded region? a. 2r(2r − π) b. 2 r (1 − π) c. 2 r (4 − π) ____ 5. Which of the following trinomials can be factored? 2 2 a. z + 33z + 9 c. z + 10z + 2 2 2 b. z + 12z + 63 d. z + 10z + 25 ____ 6. Which of the following trinomials can be factored? 2 2 a. 4c + 33c + 8 c. 4c + 13c + 8 2 2 b. 4c + 21c + 3 d. 4c + 4c + 15 1 d. r(r − 2 π) ID: A Name: ______________________ ____ ____ ID: A 7. Which polynomial, written in simplified form, represents the area of this rectangle? 2 2 c. 16x + 72xy − 40y 2 2 d. 8x + 36xy − 20y a. 8x − 36xy − 20y b. 8x + 22xy − 20y 2 2 2 2 8. Which arrow diagram shows the association “is less than” from a set of numbers to a set of numbers? a. c. b. d. 2 Name: ______________________ ____ ID: A 9. This graph shows the masses of people, m, as a function of age, a. Determine the range of the graph. a. b. R:(4, 5, 8, 12, 14, 17) R:(3, 5, 8, 10, 14, 17) c. d. R:(15, 25, 45, 55, 80, 85) R:(20, 25, 45, 65, 80, 85) ____ 10. This graph shows the volume of water remaining in a leaking hot tub as a function of time. Determine the domain and range. a. b. Domain: t ≤ 129 Range: 0 ≤ V ≤ 1800 Domain: 0 ≤ V ≤ 1800 Range: t ≤ 129 c. d. 3 Domain: 0 ≤ t ≤ 129 Range: V ≤ 1800 Domain: 0 ≤ t ≤ 129 Range: 0 ≤ V ≤ 1800 Name: ______________________ ID: A ____ 11. Which graph represents the linear function f (x) = −3x + 4? a. c. b. d. 4 Name: ______________________ ID: A ____ 12. Each graph below shows distance, d metres, as a function of time, t hours. Which graph has a rate of change of 0.75 m/h and a horizontal intercept of 3 m? a. c. b. d. 5 Name: ______________________ ID: A ____ 13. This graph shows the cost of gas. The cost, C dollars, is a function of the volume, V litres, of gas purchased. What is the volume of gas purchased when the cost is $10.45? a. b. about 11.5 L about 10.5 L c. d. about 9.5 L about 9 L ____ 14. A straight section of an Olympic downhill ski course is 34 m long. It drops 16 m in height. Determine the slope of this part of the course. 15 8 a. − c. − 8 17 8 17 b. − d. − 15 8 ____ 15. The slope of a line is 1 . What is the slope of a line that is parallel to this line? 7 a. 7 c. 2 14 b. 14 2 d. −7 ____ 16. The slope of a line is a. − b. 7 14 2 1 . What is the slope of a line that is perpendicular to this line? 7 c. d. 6 1 7 2 14 Name: ______________________ ID: A ____ 17. A line passes through D(–5, 3) and N(12, –4). Determine the coordinates of two points on a line parallel to DN. a. (6, –10) and (24, –8) c. (–10, 6) and (24, –8) b. (–10, 24) and (6, –8) d. (–10, 6) and (–8, 24) ____ 18. A line passes through R(8, 1) and F(–5, –4). Determine the coordinates of two points on a line perpendicular to RF. a. (16, –11) and (21, 2) c. (16, 2) and (21, –11) b. (2, 16) and (21, –11) d. (16, 2) and (–11, 21) 2 ____ 19. Which graph represents the equation y = − x + 1? 5 a. c. b. d. 7 Name: ______________________ ID: A ____ 20. Write an equation in slope-point form for the line that passes through A(–2, 4) and B(–9, 6). 2 2 a. y − 6 = − (x + 2) c. y − 4 = − (x + 2) 7 7 2 2 b. y + 4 = − (x − 2) d. y + 6 = (x − 2) 7 7 ____ 21. Write an equation in slope-point form for the line that passes through A(1, 4) and B(6, 8). 4 4 a. y + 8 = (x − 1) c. y − 4 = (x − 1) 5 5 4 4 b. y + 4 = − (x − 1) d. y − 8 = − (x + 1) 5 5 ____ 22. Which equation is written in general form? a. −4x − 12y + 15 = 0 b. 12x − 4y + 15 = 0 c. d. 12x = 4y − 15 1 x − 4y − 12 = 0 15 ____ 23. A line has x-intercept –9 and y-intercept 3. Determine the equation of the line in general form. a. 3x + 9y − 27 = 0 c. 3x − 9y + 27 = 0 b. 3x − 9y − 27 = 0 d. 3x + 9y + 27 = 0 ____ 24. Which linear system has the solution x = 8 and y = 2.5? a. 2x + 2y = 21 c. 2x + 2y = 8 2x – 2y = 11 x – y = 21 b. x + 2y = 8 d. x + 3y = 22 2x – 4y = 16 2x – y = 10 ____ 25. Use the graph to approximate the solution of the linear system: y = −5x − 2 y = 5x − 4 a. b. (–3, 0.2) (0, –2.8) c. d. 8 (0.2, –3) (–2.8, 0) Name: ______________________ ID: A ____ 26. Two life insurance companies determine their premiums using different formulas: Company A: p = 2a + 24 Company B: p = 2.25a + 13, where p represents the annual premium, and a represents the client’s age. Use the graph to determine the age at which both companies charge the same premium. a. 62 years b. 24 years c. 59 years ____ 27. Express each equation in slope-intercept form. –2x + 4y = 68 13x + 4y = 284 a. b. 1 x – 17 2 13 y = − x – 71 4 284 y=− x + 17 13 13 4 y=− x+ 4 13 y= c. d. 9 1 x + 17 2 13 y = − x + 71 4 4 284 y= x− 13 13 1 284 y= x− 2 13 y= d. 44 years Name: ______________________ ID: A ____ 28. Use the table of values to determine the solution of this linear system: 4x + y = 3 2x + y = −5 a. b. (–13, –13) (4, –13) c. d. (–13, 4) (4, 4) ____ 29. For each equation, identify a number you could multiply each term by to ensure that the coefficients of the variables and the constant term are integers. 5 1 47 (1) x+ y= 4 6 12 4 6 (2) x – y = 16 5 7 a. b. c. d. Multiply Multiply Multiply Multiply equation equation equation equation (1) (1) (1) (1) by by by by 35; multiply equation (2) by 12. 12; multiply equation (2) by 35. 2; multiply equation (2) by 3. 3; multiply equation (2) by 2. ____ 30. Write an equivalent system with integer coefficients. 3 438 x + 3y = 7 7 5 310 x + 5y = 6 3 a. b. 3x + 21y = 438 5x + 30y = 620 21x + 3y = 438 5x + 30y = 620 c. d. 3x + 21y = 438 30x + 5y = 620 3x + 21y = 1 5x + 30y = 1 ____ 31. The first equation of a linear system is 2x + 3y = 52. Choose a second equation to form a linear system with infinite solutions. i) 2x + 3y = –260 i i ) –10x – 15y = –260 iii) –10x + 3y = –260 iv) –10x + 3y = 255 a. Equation iii b. Equation iv c. 10 Equation i d. Equation ii Name: ______________________ ID: A ____ 32. The first equation of a linear system is –6x + 12y = –42. Choose a second equation to form a linear system with no solution. i) –6x + 12y = 126 i i ) 18x – 36y = 126 iii) 18x + 12y = 126 iv) 18x + 36y = 0 a. Equation iv b. Equation ii c. Equation iii d. Equation i ____ 33. Determine the angle of inclination of the line to the nearest tenth of a degree. a. 63.3° b. 24.2° c. 65.8° d. 26.7° ____ 34. A guy wire is attached to a tower at a point that is 10 m above the ground. The wire is anchored 21 m from the base of the tower. What angle, to the nearest degree, does the guy wire make with the ground? a. 62° b. 25° c. 28° d. 65° Short Answer 35. A regular tetrahedron with edge length 12.7 mm has a surface area of 229.0 mm2 . Determine the slant height of the tetrahedron to the nearest millimetre. . 36. Determine the volume of this composite object, which is a right square prism and a right rectangular pyramid, to the nearest tenth of a cubic metre. 11 Name: ______________________ ID: A 37. Tan B = 1.3; determine the measure of ∠B to the nearest tenth of a degree. . 2 38. Suppose you must use 2 x -tiles and twenty-two 1-tiles. Which numbers of x-tiles could you use to form a rectangle? . 39. Find and correct the error(s) in this solution of factoring by decomposition. 2 2 90y + 77y − 52 = 90y + 117y − 40y − 52 = 9y(10y + 13) + 4(10y + 13) = (10y + 13)(9y + 4) . 2 2 40. The area of a square is represented by the trinomial 36m + 84mn + 49n . Determine an expression for the perimeter of the square. . 41. Evaluate 4 625 . 12 Name: ______________________ ID: A 1 42. This is a graph of the function h (x) = − 2 x + 1. a) Determine the range value when the domain value is –2. b) Determine the domain value when the range value is –1. . 43. Graph the line with y-intercept 3 and slope –2. 44. Determine the slope of the line of this equation: 9x + 5y − 13 = 0 . 13 Name: ______________________ ID: A Problem 45. Convert 28 yd. to feet. Use unit analysis to verify the conversion. . 46. Sheila plans to place crown moulding along the top of each wall in her family room. A total of 554 in. of moulding is required. The moulding costs $1.59/ft. and is sold in 8-ft. lengths. What is the cost of the crown moulding, before taxes? . 47. What referents would you use to estimate the length, in both SI units and imperial units, of the Capilano Suspension Bridge in North Vancouver? Explain how you could measure the length in both units. . 48. Determine the measures of ∠A and ∠C to the nearest tenth of a degree. 49. For a spherical space station, this formula is used to estimate the number of rotations per minute, N, required so that the force inside the station simulates the gravity on Earth: N= 42 5 − 1 2 ⋅ r , where r is the radius of the space station, in metres π Suppose the radius of the space station is 12.7 m. Calculate the number of rotations per minute required to simulate the gravity on Earth. Write the answer to the nearest hundredth. 14 Name: ______________________ ID: A 50. Four litres of latex paint covers approximately 37 m2 and costs $52. a) Copy and complete this table. Volume of Paint, p (L) Cost, c ($) Area Covered, A ( m2 ) 0 4 8 12 16 0 52 0 37 b) Graph the area covered as a function of the volume of paint. c) Graph the area covered as a function of the cost. d) Write the domain and range of the functions in parts b and c. 15 Name: ______________________ ID: A 51. Construction workers are paving a road. The road must drop 4 cm for every 650 cm measured horizontally. a) What is the slope of the road? b) Suppose a section of the road drops 24.5 cm. How long is this section of the road measured horizontally? . 52. Sales clerks at an appliance store have a choice of two methods of payment: Plan A: $580 every two weeks plus 4.2% commission on all sales Plan B: $880 every two weeks plus 1.2% commission on all sales a) Write a linear system to model this situation. b) Graph the linear system in part a. (Either by hand or graphing calc.) c) Use the graph to solve this problem: What must the sales for a two-week period be for a clerk to receive the same salary with both plans? . 53. a) Model this situation with a linear system: To rent a car, a person is charged a daily rate and a fee for each kilometre driven. When Chena rented a car for 15 days and drove 800 km, the charge was $715.00. When she rented the same car for 25 days and drove 2250 km, the charge was $1512.50. b) Determine the daily rate and the fee for each kilometre driven. Verify the solution. 16 ID: A Math 10C Course Review Answer Section MULTIPLE CHOICE 1. ANS: REF: TOP: 2. ANS: REF: TOP: 3. ANS: REF: TOP: 4. ANS: REF: TOP: 5. ANS: REF: TOP: 6. ANS: REF: TOP: 7. ANS: LOC: 8. ANS: LOC: 9. ANS: REF: TOP: 10. ANS: REF: TOP: 11. ANS: REF: TOP: 12. ANS: REF: TOP: 13. ANS: REF: TOP: 14. ANS: LOC: 15. ANS: REF: TOP: C PTS: 1 DIF: Easy 1.2 Measuring Length and Distance LOC: 10.M1 Measurement KEY: Conceptual Understanding C PTS: 1 DIF: Easy 1.2 Measuring Length and Distance LOC: 10.M1 Measurement KEY: Conceptual Understanding C PTS: 1 DIF: Easy 1.2 Measuring Length and Distance LOC: 10.M1 Measurement KEY: Conceptual Understanding C PTS: 1 DIF: Moderate 3.3 Common Factors of a Polynomial LOC: 10.AN5 Algebra and Number KEY: Procedural Knowledge D PTS: 1 DIF: Easy 3.4 Modelling Trinomials as Binomial Products LOC: 10.AN5 Algebra and Number KEY: Procedural Knowledge A PTS: 1 DIF: Easy 3.4 Modelling Trinomials as Binomial Products LOC: 10.AN5 Algebra and Number KEY: Procedural Knowledge D PTS: 1 DIF: Moderate REF: 3.7 Multiplying Polynomials 10.AN4 TOP: Algebra and Number KEY: Procedural Knowledge D PTS: 1 DIF: Moderate REF: 5.1 Representing Relations 10.RF4 TOP: Relations and Functions KEY: Conceptual Understanding D PTS: 1 DIF: Easy 5.5 Graphs of Relations and Functions LOC: 10.RF1 Relations and Functions KEY: Conceptual Understanding D PTS: 1 DIF: Easy 5.7 Interpreting Graphs of Linear Functions LOC: 10.RF5 Relations and Functions KEY: Conceptual Understanding A PTS: 1 DIF: Easy 5.7 Interpreting Graphs of Linear Functions LOC: 10.RF5 Relations and Functions KEY: Procedural Knowledge B PTS: 1 DIF: Easy 5.7 Interpreting Graphs of Linear Functions LOC: 10.RF5 Relations and Functions KEY: Procedural Knowledge C PTS: 1 DIF: Easy 5.7 Interpreting Graphs of Linear Functions LOC: 10.RF8 Relations and Functions KEY: Conceptual Understanding B PTS: 1 DIF: Moderate REF: 6.1 Slope of a Line 10.RF5 TOP: Relations and Functions KEY: Procedural Knowledge C PTS: 1 DIF: Easy 6.2 Slopes of Parallel and Perpendicular Lines LOC: 10.RF3 Relations and Functions KEY: Conceptual Understanding 1 ID: A 16. ANS: REF: TOP: 17. ANS: REF: TOP: 18. ANS: REF: TOP: 19. ANS: REF: LOC: 20. ANS: REF: LOC: KEY: 21. ANS: REF: LOC: KEY: 22. ANS: REF: LOC: 23. ANS: REF: LOC: 24. ANS: REF: TOP: 25. ANS: REF: TOP: 26. ANS: REF: TOP: 27. ANS: REF: LOC: 28. ANS: REF: LOC: 29. ANS: REF: LOC: 30. ANS: REF: LOC: A PTS: 1 DIF: Easy 6.2 Slopes of Parallel and Perpendicular Lines LOC: 10.RF3 Relations and Functions KEY: Conceptual Understanding C PTS: 1 DIF: Moderate 6.2 Slopes of Parallel and Perpendicular Lines LOC: 10.RF3 Relations and Functions KEY: Procedural Knowledge C PTS: 1 DIF: Moderate 6.2 Slopes of Parallel and Perpendicular Lines LOC: 10.RF3 Relations and Functions KEY: Procedural Knowledge B PTS: 1 DIF: Easy 6.4 Slope-Intercept Form of the Equation for a Linear Function 10.RF7 TOP: Relations and Functions KEY: Conceptual C PTS: 1 DIF: Easy 6.5 Slope-Point Form of the Equation for a Linear Function 10.RF6 TOP: Relations and Functions Conceptual Understanding | Procedural Knowledge C PTS: 1 DIF: Easy 6.5 Slope-Point Form of the Equation for a Linear Function 10.RF6 TOP: Relations and Functions Conceptual Understanding | Procedural Knowledge B PTS: 1 DIF: Easy 6.6 General Form of the Equation for a Linear Relation 10.RF6 TOP: Relations and Functions KEY: Conceptual C PTS: 1 DIF: Moderate 6.6 General Form of the Equation for a Linear Relation 10.RF6 TOP: Relations and Functions KEY: Conceptual A PTS: 1 DIF: Easy 7.1 Developing Systems of Linear Equations LOC: 10.RF9 Relations and Functions KEY: Conceptual Understanding C PTS: 1 DIF: Easy 7.2 Solving a System of Linear Equations Graphically LOC: 10.RF9 Relations and Functions KEY: Conceptual Understanding D PTS: 1 DIF: Easy 7.2 Solving a System of Linear Equations Graphically LOC: 10.RF9 Relations and Functions KEY: Conceptual Understanding C PTS: 1 DIF: Moderate 7.3 Using Graphing Technology to Solve a System of Linear Equations 10.RF9 TOP: Relations and Functions KEY: Conceptual B PTS: 1 DIF: Easy 7.3 Using Graphing Technology to Solve a System of Linear Equations 10.RF9 TOP: Relations and Functions KEY: Conceptual B PTS: 1 DIF: Easy 7.4 Using a Substitution Strategy to Solve a System of Linear Equations 10.RF9 TOP: Relations and Functions KEY: Conceptual A PTS: 1 DIF: Easy 7.4 Using a Substitution Strategy to Solve a System of Linear Equations 10.RF9 TOP: Relations and Functions KEY: Conceptual 2 Understanding Understanding Understanding Understanding Understanding Understanding Understanding ID: A 31. ANS: REF: TOP: 32. ANS: REF: TOP: 33. ANS: LOC: 34. ANS: LOC: D PTS: 1 DIF: Moderate 7.6 Properties of Systems of Linear Equations LOC: 10.RF9 Relations and Functions KEY: Conceptual Understanding D PTS: 1 DIF: Moderate 7.6 Properties of Systems of Linear Equations LOC: 10.RF9 Relations and Functions KEY: Conceptual Understanding B PTS: 1 DIF: Easy REF: 2.1 The Tangent Ratio 10.M4 TOP: Measurement KEY: Procedural Knowledge B PTS: 1 DIF: Easy REF: 2.1 The Tangent Ratio 10.M4 TOP: Measurement KEY: Procedural Knowledge SHORT ANSWER 35. ANS: 9 mm PTS: 1 LOC: 10.M3 36. ANS: 370.5 m3 DIF: Moderate REF: 1.4 Surface Areas of Right Pyramids and Right Cones TOP: Measurement KEY: Procedural Knowledge PTS: 1 LOC: 10.M3 37. ANS: Ö ∠B = 52.4° DIF: Easy REF: 1.7 Solving Problems Involving Objects TOP: Measurement KEY: Procedural Knowledge PTS: 1 LOC: 10.M4 38. ANS: 15, 24, and 45 DIF: Easy REF: 2.1 The Tangent Ratio TOP: Measurement KEY: Procedural Knowledge PTS: 1 DIF: Moderate REF: 3.4 Modelling Trinomials as Binomial Products LOC: 10.AN5 TOP: Algebra and Number KEY: Procedural Knowledge 39. ANS: 2 2 90y + 77y − 52 = 90y + 117y − 40y − 52 = 9y(10y + 13) − 4(10y + 13) = (10y + 13)(9y − 4) PTS: 1 LOC: 10.AN5 40. ANS: 4 (6m + 7n ) DIF: Moderate REF: 3.6 Polynomials of the Form ax^2 + bx + c TOP: Algebra and Number KEY: Procedural Knowledge PTS: 1 LOC: 10.AN5 DIF: Moderate REF: 3.8 Factoring Special Polynomials TOP: Algebra and Number KEY: Procedural Knowledge 3 ID: A 41. ANS: 5 PTS: 1 DIF: Easy REF: 4.1 Estimating Roots LOC: 10.AN2 TOP: Algebra and Number KEY: Conceptual Understanding 42. ANS: a) When the domain value is –2, the range value is 2. b) When the range value is –1, the domain value is 4. PTS: 1 LOC: 10.RF8 43. ANS: DIF: Moderate REF: 5.5 Graphs of Relations and Functions TOP: Relations and Functions KEY: Conceptual Understanding PTS: 1 DIF: Easy REF: 6.4 Slope-Intercept Form of the Equation for a Linear Function LOC: 10.RF6 TOP: Relations and Functions KEY: Procedural Knowledge 44. ANS: 9 − 5 PTS: 1 LOC: 10.RF6 DIF: Easy REF: 6.6 General Form of the Equation for a Linear Relation TOP: Relations and Functions KEY: Conceptual Understanding 4 ID: A PROBLEM 45. ANS: Since 1 yd. = 3 ft., to convert yards to feet, multiply by 3. 28 yd. = 28(3 ft.) 28 yd. = 84 ft. Write a conversion factor for yards and feet, with feet in the numerator: Then, 28 yd. × 28 yd. 3 ft. 3 ft. = × 1 yd. 1 1 yd. = 28 yd. 3 ft. × 1 1 yd. = 84 ft. 1 = 84 ft. Since the measurements are equal, the conversion is verified. PTS: 1 LOC: 10.M2 DIF: Moderate REF: 1.1 Imperial Measures of Length TOP: Measurement KEY: Procedural Knowledge 5 ID: A 46. ANS: To convert inches to feet and inches, divide by 12. 554 554 in. = ft. 12 2 554 in. = 46 ft. 12 554 in. = 46 ft. 2 in. Sheila requires approximately 47 ft. of moulding. To find the number of 8-ft. lengths Sheila needs, divide 47 by 8. 47 ft. 7 =5 8 ft. 8 The number of 8-ft. lengths is greater than 5, so Sheila must buy 6 lengths. The total number of feet in 6 lengths is: 6(8 ft.) = 48 ft. The cost, C, is: C = 48($1.59) C = $76.32 Before taxes, the crown moulding will cost $76.32. PTS: 1 DIF: Moderate REF: 1.1 Imperial Measures of Length LOC: 10.M2 TOP: Measurement KEY: Problem-Solving Skills 47. ANS: Sample answer: I would walk along the bridge, counting the number of large steps I take to go from one end of the bridge to the other. Each large step is about 1 yd., so the number of steps is the approximate length of the bridge, in yards. Since 1 m is slightly longer than 1 yd., the number of metres that represent the length of the bridge is slightly less than the number of yards. Students may use different referents to solve this problem. PTS: 1 DIF: Moderate REF: 1.2 Measuring Length and Distance LOC: 10.M1 TOP: Measurement KEY: Communication | Problem-Solving Skills 6 ID: A 48. ANS: Determine the measure of ∠C first. In right ΔABC: adjacent cosC = hypotenuse cosC = BC AC cosC = 11 23 ∠C = 61.4281. . . ° ∠A + ∠C = 90° ∠A = 90° − ∠C So, ∠A = 90° − 61.4281. . . ° ∠A = 28.5718. . . ° ∠C is approximately 61.4° and ∠A is approximately 28.6°. PTS: 1 DIF: Moderate REF: 2.4 The Sine and Cosine Ratios LOC: 10.M4 TOP: Measurement KEY: Problem-Solving Skills 49. ANS: Use the formula. Substitute: r = 12.7 N= = 42 5 π 42 5 π − ⋅ 12.7 ⋅ 1 2 1 12.7 = 8.3884… So, the space station simulates the gravity on Earth at about 8.39 rotations/min. PTS: 1 LOC: 10.AN3 DIF: Moderate REF: 4.5 Negative Exponents and Reciprocals TOP: Algebra and Number KEY: Problem-Solving Skills 7 ID: A 50. ANS: a) Volume of Paint, p (L) Cost, c ($) 0 4 8 12 16 0 52 104 156 208 Area Covered, A ( m2 ) 0 37 148 74 111 b) c) d) Part b: domain: 0 ≤ p ≤ 16; range: 0 ≤ A ≤ 148 Part c: domain: 0 ≤ c ≤ 208; range: 0 ≤ A ≤ 148 PTS: 1 DIF: Difficult REF: 5.5 Graphs of Relations and Functions LOC: 10.RF1 TOP: Relations and Functions KEY: Communication | Problem-Solving Skills 8 ID: A 51. ANS: a) Slope = rise run 4 650 2 Slope = − 325 Slope = − The slope of the road is − 2 . 325 b) The distance the road drops is the rise. Since the road drops, the rise is negative. The section of the road measured horizontally is the run. rise Slope = run 2 −24.5 − = 325 run ˆ ˆ Ê −2 ˜ Ê −24.5 ˜ ˜ ˜ run Á = run Á ˜ ˜ ˜ ˜ 325 run ˜ ˜ Ë Ë ˜ ˜ ˜ ˜ ¯ ¯ −2 (run ) = −24.5 325 ˆ Ê −2 (run ) ˜ ˜ ˜ 325 Á = (325)(–24.5) ˜ ˜ 325 Ë ˜ ˜ ¯ ˜ (−2) run = (325)(–24.5) (−2) run = −7963 run = 3981.25 The section of the road measured horizontally is 3981.25 cm long. PTS: 1 DIF: Moderate REF: 6.1 Slope of a Line LOC: 10.RF5 TOP: Relations and Functions KEY: Communication | Problem-Solving Skills 9 ID: A 52. ANS: a) Let P represent the clerk’s two-week salary, in dollars, and s represent the clerk’s two-week sales, in dollars. Then, a linear system is: P = 580 + 0.042s P = 880 + 0.012s b) P = 580 + 0.042s P = 880 + 0.012s For each equation, determine the P-intercept and the coordinates of another point on the line. For equation 1: P = 580 + 0.042s Substitute: s = 0 P = 580 Substitute: s = 10 000 P = 580 + 0.042 × 10 000 P = 580 + 420 P = 1000 On a grid, use a scale of 1 square to 200 units on the P-axis, and a scale of 2 squares to 10 000 units on the s-axis. Mark a point at 580 on the P-axis and mark a point at (10 000, 1000). Join the points with a line. For equation 2: P = 880 + 0.012s Substitute: s = 0 P = 880 Substitute: s = 10 000 P = 880 + 0.012 × 10 000 P = 880 + 120 P = 1000 On the grid, mark a point at 1000 on the P-axis and mark a point at (10 000, 1000). Join the points with a line. 10 ID: A c) From the graph, a clerk will receive the same salary, $1000, with both plans when the two-week sales is $10 000. Check that this solution satisfies both equations. Substitute P = 1000 and s = 10 000 in each equation. For equation 1: P = 580 + 0.042s L.S. = P R.S. = 580 + 0.042s = 1000 = 580 + 0.042(10 000) = 580 + 420 = 1000 For equation 2: P = 880 + 0.012s L.S. = P R.S. = 880 + 0.012s = 1000 = 880 + 0.012(10 000) = 880 + 120 = 1000 Since the left side is equal to the right side for each equation, the solution is correct. PTS: 1 DIF: Difficult REF: 7.2 Solving a System of Linear Equations Graphically LOC: 10.RF9 TOP: Relations and Functions KEY: Communication | Problem-Solving Skills 11 ID: A 53. ANS: a) Let d dollars represent the daily rate and let k dollars represent the fee for each kilometre driven. The linear system is: 15d + 800k = 715 25d + 2250k = 1512.5 b) Multiply equation by 25 and equation 25 × equation : 25(15d + 800k = 715) 375d + 20000k = 17875 15 × equation by 15, then subtract to eliminate d. : 15(25d + 2250k = 1512.5) 375d + 33750k = 22687.5 Subtract equation from equation 375d + 20000k = 17875 −(375d + 33750k = 22687.5) − 13750k = −4812.5 . k = 0.35 Substitute k = 0.35 in equation 15d + 800k = 715 . 15d + 800(0.35) = 715 15d + 280 = 715 15d = 435 d = 29 Verify the solution. In each equation, substitute: k = 0.35 and d = 29 15d + 800k = 715 L.S. = 15d + 800k 25d + 2250k = 1512.5 L.S. = 25d + 2250k = 15(29) + 800(0.35) = 25(29) + 2250(0.35) = 435 + 280 = 725 + 787.5 = 715 = 1512.5 = R.S. = R.S. So, the daily rate is $29 and the fee for each kilometre driven is $0.35. PTS: 1 DIF: Difficult REF: 7.5 Using an Elimination Strategy to Solve a System of Linear Equations LOC: 10.RF9 TOP: Relations and Functions KEY: Problem-Solving Skills 12