Algebra Multiple Choice Study Guide Answer Section MULTIPLE CHOICE 1. ANS: B Solve the equation. Substitute 8 for x and simplify. Feedback A B C D Find the value of x by solving the equation. Then substitute it for x in the given expression and simplify. Correct! Subtract the terms in the right order. Find the value of x by solving the equation. Then substitute it for x in the given expression and simplify. PTS: 1 DIF: Advanced NAT: 12.5.4.a TOP: 2-2 Solving Equations by Multiplying or Dividing 2. ANS: C Since is subtracted from subtraction. , add to both sides to undo the Since f is divided by 45, multiply both sides by 45 to undo the division. Simplify. Feedback A B C D First, add to undo the subtraction. Then, multiply to undo the division. Check your signs. Correct! First, add to undo the subtraction. Then, multiply to undo the division. PTS: OBJ: NAT: 3. ANS: 1 DIF: Average REF: Page 93 2-3.2 Solving Two-Step Equations That Contain Fractions 12.5.4.a TOP: 2-3 Solving Two-Step and Multi-Step Equations A Use the Commutative Property of Addition. Combine like terms. Since 10 is added to 17a, subtract 10 from both sides to undo the addition. Since a is multiplied by 17, divide both sides by 17 to undo the multiplication. Feedback A B C D Correct! Check your signs. Combine like terms, and then solve. Combine like terms, and then solve. PTS: 1 DIF: Average REF: Page 93 OBJ: 2-3.3 Simplifying Before Solving Equations NAT: 12.5.3.c TOP: 2-3 Solving Two-Step and Multi-Step Equations 4. ANS: B Let d be the distance (in miles) to the movies, then is the number of miles after the first mile. So a formula for the total charge could be first mile charge 4.00 + + rate after first mile 2.75 = total charge = 20.50 2.75 2.75 = = 20.50 4.00 16.5 Subtract 4.00 from each side. Divide both sides by 2.75. = d d = 6 = = 6+1 7 Add 1 to both sides. Feedback A B C D Add one for the first mile. Correct! The mileage rate is the charge for each mile after the first mile. Subtract the charge for the first mile. PTS: 1 NAT: 12.5.3.b 5. ANS: D DIF: Average REF: Page 94 OBJ: 2-3.4 Problem-Solving Application TOP: 2-3 Solving Two-Step and Multi-Step Equations To collect the variable terms on one side, subtract 50q from both sides. Since 81 is subtracted from 2q, add 81 to both sides to undo the subtraction. Since q is multiplied by 2, divide both sides by 2 to undo the multiplication. Feedback A B C D Check your signs. After adding to undo the subtraction, divide to undo the multiplication. First, collect the variable terms on one side. Then, add to undo the subtraction. Correct! PTS: OBJ: TOP: 6. ANS: 1 DIF: Average REF: Page 100 2-4.1 Solving Equations with Variables on Both Sides 2-4 Solving Equations with Variables on Both Sides C Locate V in the equation. NAT: 12.5.4.a Since V is divided by I, multiply both sides by I to undo the division. Feedback A B C D Multiply both sides by I to isolate r. Multiply both sides by I to isolate r. Correct! Multiply both sides by I to isolate r. PTS: OBJ: TOP: 7. ANS: 1 DIF: Basic REF: Page 108 2-5.2 Solving Formulas for a Variable NAT: 12.5.4.f 2-5 Solving for a Variable KEY: literal equation | solving | variables D Divide both sides by 7. What numbers are 7 units from 0? Case 1: x–6=7 Case 2: x – 6 = –7 Rewrite the equation as two cases. The solutions are x = 13 or x = –1. Feedback A B C Divide before you add or subtract. There are two cases to solve. Absolute value means distance from zero. Solve the second case when the number inside the absolute value is negative. Divide before you add or subtract. D Correct! PTS: 1 DIF: Average REF: Page 294 OBJ: 2-Ext.1 Solving Absolute-Value Equations TOP: 2-Ext Solving Absolute-Value Equations 8. ANS: C First, isolate the absolute value expression. Subtract 8 from both sides. The absolute value expression is equal to a negative number, which is impossible. The equation has no solution. Feedback A B C D An absolute value must be greater than or equal to 0. Isolate the absolute value by subtracting the term outside absolute value bars. Correct! Subtract the term outside the absolute value bars. PTS: 1 DIF: Average REF: Page 295 OBJ: 2-Ext.2 Special Cases of Absolute-Value Equations TOP: 2-Ext Solving Absolute-Value Equations 9. ANS: C Use the variable m. The arrow points to the right, so use either > or . The solid circle at –3 means that –3 is a solution, so use . Feedback A B C D The arrow should point in the same direction as the inequality symbol. The endpoint is not a solution. Correct! The endpoint is not a solution. PTS: 1 DIF: Basic REF: Page 170 OBJ: 3-1.3 Writing an Inequality from a Graph NAT: 12.5.4.c TOP: 3-1 Graphing and Writing Inequalities 10. ANS: D The variable n must be greater than or equal to 500 yards for a swimmer to make the team. The graph should include the number 500 (solid circle at 500) and all the numbers to the right of 500 on the number line. Feedback A B C D The number of yards must be greater than or equal to 500, not less than 500. The number of yards must be greater than or equal to 500, not less than 500. The number 500 should be included in the solution. Correct! PTS: 1 NAT: 12.5.4.c DIF: Average REF: Page 170 OBJ: 3-1.4 Application TOP: 3-1 Graphing and Writing Inequalities 11. ANS: A Let d represent the amount of money in dollars Denise must save to reach her goal. $365 plus additional amount of money is at least $635 in dollars 365 + d 635 Since 365 is added to d, subtract 365 from both sides to undo the addition. 365 365 Check the endpoint 270 and a number that is greater than the endpoint. Feedback A B C D Correct! You should be solving an inequality, not an equation. Subtract from both sides of the inequality. Check the endpoint to see if you get a true statement. PTS: 1 DIF: Average REF: Page 176 OBJ: 3-2.3 Application NAT: 12.5.4.c TOP: 3-2 Solving Inequalities by Adding and Subtracting 12. ANS: B Use inverse operations to undo the operations in the inequality one at a time. n – 4 3 n –7 –10 –8 –6 –4 –2 0 2 4 6 8 10 Use a solid circle when the value is included in the graph, such as with or Use an empty circle when the value is not included, such as with > or <. Feedback A B C D If you divide both sides of the inequality by a negative number, reverse the inequality symbol. If you divide by a positive number, do not reverse the inequality symbol. Correct! Use inverse operations to undo the operations in the inequality one at a time. Check your calculations when using inverse operations to isolate the variable. PTS: OBJ: TOP: MSC: 13. ANS: 1 DIF: Basic REF: Page 188 3-4.1 Solving Multi-Step Inequalities NAT: 12.5.4.a 3-4 Solving Two-Step and Multi-Step Inequalities KEY: solving | two-step inequality solving | two-step inequality C AND Write the compound inequality using AND. Solve each simple inequality. Divide to undo the multiplication. AND First, graph the solutions of each simple inequality. Then, graph the intersection by finding where the two graphs overlap. Feedback A B C D Check the endpoints to see whether they are included in the solutions. Check the endpoints to see whether they are included in the solutions. Correct! Check the inequality symbols. A number cannot be less than 1 AND greater than or equal to 4. PTS: 1 DIF: Average REF: Page 203 OBJ: 3-6.2 Solving Compound Inequalities Involving AND TOP: 3-6 Solving Compound Inequalities 14. ANS: D The graph intersects the x-axis at (10, 0). The x-intercept is 10. The graph intersects the y-axis at (0, 5). The y-intercept is 5. NAT: 12.5.4.c Feedback A B C D Check the x-intercept. If the x-intercept is to the left of the origin, it is negative. The x-axis is the horizontal (left-right) axis; the y-axis is the vertical (up-down) axis. Check the y-intercept. If the y-intercept is below the origin, it is negative. Correct! PTS: 1 DIF: Basic REF: Page 303 NAT: 12.5.1.e TOP: 5-2 Using Intercepts KEY: linear equation | x-intercept | y-intercept | intercepts 15. ANS: B To find the slope, use the coordinates of two points on the line. OBJ: 5-2.1 Finding Intercepts Starting at one point, count the units down (negative units) or up (positive units) and to the right (positive units) or to the left (negative units) to arrive at the other point. The units up or down are the rise. The units to the right or to the left are the run. Write a fraction with the rise in the numerator and the run in the denominator. Simplify the fraction. Feedback A B C D To find the slope, choose two points on the line. Divide the rise from one point to the next by the run. Correct! When finding slope, the numerator should be the rise (change in y-values) and the denominator should be the run (change in x-values). Check the signs for rise and run. If the line rises from left to right, the slope is positive; if it falls, the slope is negative. PTS: 1 NAT: 12.5.2.b 16. ANS: D DIF: Basic REF: Page 311 TOP: 5-3 Rate of Change and Slope Use the slope formula. OBJ: 5-3.3 Finding Slope KEY: line | slope Substitute = 3 5 for and for . Simplify. Feedback A B C D Divide the difference in y-values by the difference in x-values. Use the slope formula. First, substitute the coordinates of the first point into (x1, x2) and the coordinates of the second point into (y1, y2) of the slope formula. Then, simplify. Correct! PTS: 1 DIF: Basic REF: Page 320 OBJ: 5-4.1 Finding Slope by Using the Slope Formula NAT: 12.5.2.b TOP: 5-4 The Slope Formula 17. ANS: A Find the x-intercept by substituting x = 0 into the equation. Find the y-intercept by substituting y = 0 into the equation. Use the two intercept points and the slope formula, , to calculate the slope. Feedback A B C D Correct! Check the sign. Slope is the ratio of rise to run. First, find the x- and y-intercepts. Then, substitute those points into the slope formula. PTS: 1 DIF: Average REF: Page 322 OBJ: 5-4.4 Finding Slope from an Equation NAT: 12.5.2.c TOP: 5-4 The Slope Formula 18. ANS: A Write all the equations in slope-intercept form (y = mx + b). The equations that have the same slope but different y-intercepts are parallel lines. Feedback A B C D Correct! Put the lines in slope-intercept form and look for lines with equal slopes. Not all the lines have the same slope. Note that Line 1 and Line 3 are in slope intercept form, but the coefficients of x are different. Put the lines in slope-intercept form and look for lines with equal slopes. PTS: 1 DIF: Average REF: Page 349 OBJ: 5-8.1 Identifying Parallel Lines NAT: 12.3.3.g TOP: 5-8 Slopes of Parallel and Perpendicular Lines 19. ANS: C Step 1 3x – 6y = 12 2x + 6y = –12 The y-terms have opposite coefficients. 5x = 0 Add the equations to eliminate the y terms. x=0 Step 2 3(0) – 6y = 12 0 – 6y = 12 – 6y = 12 y = –2 Substitute for x in one of the original equations. Simplify and solve for y. (0, –2) Write the solution as an ordered pair. Feedback A B C D This is a solution of the first equation, but it is not a solution of the second equation. Use elimination to find a solution of both equations. You switched the x- and y-coordinates. Correct! Add the equations to eliminate the variable, not subtract. PTS: 1 DIF: Basic REF: Page 398 OBJ: 6-3.1 Elimination Using Addition NAT: 12.5.4.g TOP: 6-3 Solving Systems by Elimination KEY: linear equations | system of equations | solving | elimination 20. ANS: A Let z be the number of zebra fish and let n be the number of neon tetras that Marsha bought. Then solve the following system of equations. Marsha spent $25.80. Marsha bought 13 fish. Multiply the second equation by –2.10 Add the two equations to eliminate the z term. Solve for n. To solve for z, substitute 6 for n in the first equation. Simplify. Solve for z. Feedback A B C D Correct! Write an equation expressing the total cost and a second equation expressing the total number of fish. Solve for z and n using elimination. You switched the prices of zebra fish and neon tetras. Write an equation expressing the total cost and a second equation expressing the total number of fish. Solve for z and n using elimination. PTS: 1 DIF: Average REF: Page 400 OBJ: 6-3.4 Application NAT: 12.5.4.g TOP: 6-3 Solving Systems by Elimination 21. ANS: D Write each equation in slope-intercept form. y = –x + 8 y = –x + 7 The lines both have slope –1 but different y-intercepts, so they are parallel. Parallel lines never intersect so the system has no solutions and is inconsistent. Feedback A B C D Write both equations in slope-intercept form to see if the lines are parallel. Write both equations in slope-intercept form to see if the lines are parallel or the same line. Only lines with the same graph have infinitely many solutions. Write both equations in slope-intercept form to see if the lines are parallel. Correct! PTS: 1 DIF: Average REF: Page 406 NAT: 12.5.4.g TOP: 6-4 Solving Special Systems 22. ANS: A Substitute (8, 5) for (x, y) in . , false (8, 5) is not a solution of OBJ: 6-4.1 Systems with No Solution . Feedback A B Correct! Substitute the values for (x, y) into the inequality to see if the ordered pair is a solution. PTS: 1 DIF: Basic REF: Page 414 OBJ: 6-5.1 Identifying Solutions of Inequalities TOP: 6-5 Solving Linear Inequalities 23. ANS: C Step 1. Solve the inequality for y. Step 2. Graph the boundary line NAT: 12.5.4.a . Use a dashed line for . Step 3. The inequality is , so shade above the line. Feedback A B C D The shaded region includes points that make the inequality true. Check the boundary and the shading. Correct! The line is solid only when the operator is not > or <. PTS: OBJ: TOP: 24. ANS: REF: OBJ: NAT: 1 DIF: Average REF: Page 415 6-5.2 Graphing Linear Inequalities in Two Variables NAT: 12.5.4.a 6-5 Solving Linear Inequalities B PTS: 1 DIF: L2 Thinking with Mathematical Models | Multiple Choice Investigation 2: Linear Models and Equations NAEP A1f| NAEP A2b| NAEP A2c| NAEP A2d| NAEP A4a| NAEP A4c| NAEP A4d| NAEP D1a| 25. 26. 27. 28. NAEP D2e STA: 8NJ 4.1.8.C.3| 8NJ 4.3.8.A.1a| 8NJ 4.3.8.B.1b| 8NJ 4.3.8.C.1| 8NJ 4.3.8.C.2a TOP: Problem 2.4 Intersecting Linear Models KEY: slope | parallel ANS: C PTS: 1 DIF: L2 REF: Thinking with Mathematical Models | Multiple Choice OBJ: Investigation 3: Inverse Variation NAT: NAEP A2a| NAEP A2b| NAEP A3a| NAEP D1a| NAEP D2e STA: 8NJ 4.1.8.A.3| 8NJ 4.3.8.A.1a| 8NJ 4.3.8.A.1b| 8NJ 4.3.8.A.1c| 8NJ 4.3.8.C.1| 8NJ 4.3.8.C.2a TOP: Problem 3.2 Inverse Variation Patterns KEY: inverse variation ANS: D PTS: 1 DIF: L2 REF: Thinking with Mathematical Models | Multiple Choice OBJ: Investigation 3: Inverse Variation NAT: NAEP A2a| NAEP A2b| NAEP A3a| NAEP D1a| NAEP D2e STA: 8NJ 4.1.8.A.3| 8NJ 4.3.8.A.1a| 8NJ 4.3.8.A.1b| 8NJ 4.3.8.A.1c| 8NJ 4.3.8.C.1| 8NJ 4.3.8.C.2a TOP: Problem 3.2 Inverse Variation Patterns KEY: inverse variation ANS: B PTS: 1 DIF: L2 REF: Thinking with Mathematical Models | Multiple Choice OBJ: Investigation 3: Inverse Variation NAT: NAEP A2a| NAEP A2b| NAEP A3a| NAEP D1a| NAEP D2e STA: 8NJ 4.1.8.A.3| 8NJ 4.3.8.A.1a| 8NJ 4.3.8.A.1b| 8NJ 4.3.8.A.1c| 8NJ 4.3.8.C.1| 8NJ 4.3.8.C.2a TOP: Problem 3.2 Inverse Variation Patterns KEY: inverse variation ANS: D PTS: 1 DIF: L1 REF: Growing Growing Growing | Skills Practice Investigation 1 OBJ: Investigation 1: Exponential Growth NAT: NAEP G3d STA: 8NJ 4.1.8.B.1a| 8NJ 4.1.8.B.1b| 8NJ 4.1.8.B.2| 8NJ 4.3.8.A.1a| 8NJ 4.3.8.A.1d| 8NJ 4.3.8.A.1e| 8NJ 4.5.8.A.3 TOP: Problem 1.2 Representing Exponential Relationships KEY: exponent | power