MA 108 Review (1) Find the value of 7 x 5 x 10 when (a) x = 3 (b) x = −2 (2) Write an equivalent expression in symbols: (a) the difference of a number and twice the sum of the number and 5 (b) the quotient of − 20 and a number is decreased by twice the number (3) Apply the distributive property and simplify when possible (a) 7(2x − 3) (b) 4(x + 5) − 2x 23 6 610 9 2 3 (4) Do the indicated operations and simplify (a) 310 9 620 19 (b) 6 5 2 (c) 57 9 3100 97 45 48 10 2 1 12 3 (d) 67 10 6 1 2 2 (e) (5) Solve (a) 4x 3 2x 11 (b) 35c 1 2 13c 3 (e) 42 x 1 7 x 3x 2 (f) 4 x 51 x 6 (f) (c) x 6 7 4 32 36 16 1 2 7 7 2x 6 6 (d) 3w 2 2w 3 4 (g) 22x 5 3x 7 x 3 (7) Solve V (6) S 4lw 2wh Find h when S = 102, l = 7, w = 3 1 Ah for A 3 (8) Solve A = P + PRT for T. (9) Solve S 2 rh 2 r 2 for h (10) The length of a rectangular garden is 6 meters. If 21 meters of fencing are required to fence the garden, find its width. (11) Piranhas require 1.5 cubic feet of water per fish to keep a healthy environment. Find the maximum number of piranhas you could put in a tank measuring: length = 8 ft, width = 6 ft, and height = 3 ft. (12) Maria’s Pizza sells one 16-inch cheese pizza or two 10-inch cheese pizzas for $9.99. Which size gives more pizza for $9.99? (Hint: Area of a circle = r 2 ) (13) Ed has $2.45 in nickels and quarters. If he has twice as many nickels as he has quarters, how many of each coin does he have? 2 4 (14) Solve the linear inequalities. Express answers in interval notation. (a) x (b) 5t 3 5 5 5 2 3 5 4 5x 3x 7 (c) x x 5 x (d) x 3 x 3 x 1 (e) 3 2 9 3 2 (15) Solve the compound inequalities. Express answers in interval notation. 5 3x 2 (a) 5x 2 0 and 3x 9 (b) 3x 4 2 or 3x 4 10 (c) 2 2 (16) Add. 11x 3 12 x 2 x 3 x 3 10 x 5 (17) Subtract. 12 y 5 12 y 3 y 3 y 4 y 3 12 y (18) Subtract x 4 from 4x 4 (19) Subtract (9x + 8) from the sum of 3x 2 2 x x 3 2 and 5x 2 8x x 3 4 (20) Multiply: (a) 4 x x 2 3x 11 (b) 5x 9 y 3x 2 y (c) 5 x 4 x 2 x 4 (d) 3x 23x 2 (e) 2 y 4 2 (f) 2x 62 x 1 8x 4 x 6 x 2 4 x 3 12 x 2 x 12 6 x 2 17 x 4 (b) (c) 2x 3 x3 2x 2 3 2 (22) Factor out the greatest common factor: (a) 5 x y 15 x y 10 xy (b) 2xx y x y (23) Factor by grouping: (a) 2 y 8 xy 4 x (b) 4 x 2 8 xy 3x 6 y (24) Factor completely: (a) x 2 8 x 15 (b) 2t 2 24t 64 (c) 2 x 2 7 x 99 (d) 15 x 2 16 x 15 (e) x 2 16 x 64 (f) 25 x 2 9 (g) y 4 81 (h) 6 x 3 6 x 2 120 x 3 2 (21) Divide: (a) (25) Solve: (a) 2 x 2 4 x 0 (b) x 2 12 x 35 0 (c) 6 y 2 19 y 10 0 (d) 2 x 2 3x 14 (e) t t 7 12 (f) x 2 3x 2 5 x 2x 1 x 1 x 1 2p 2 p 6 2 (e) p3 p p 3p (26) Add or subtract the rational expressions. Simplify answers. (a) (c) 4y 5 2 2 y 1 y 2y 1 (d) t 5t 4 2 t2 t t 2t 2 (b) y 8 y2 2 y 1 1 1 1 1 x2 z 1 2z 5 2 (b) (c) x 6 4 x x3 x3 z 1 z 2 z 3z 2 5 2 x 1 (e) x2 x3 x3 (27) Solve the rational equations. (a) (d) 3 1 10 2 x 1 1 x x 1 3 x2 (c) x = 4 (d) y = 3 4 (29) For the linear equations in #28, find the slope, x-intercept and the y-intercept. (30) Determine if the lines are parallel, perpendicular or neither. (a) x + y = 2, y = x + 5 1 y x (b) 3x + 6y = 1, (c) 2x + 3y = 9, 3x – 2y = 5 (d) y = 5, x=3 2 (31) Find the slope of the line that goes through the points (4, -2), (-3, -7) (32) Find the equation for the line that goes through the point (1, -2) and has slope -3. 2 (33) Find the equation for the line that goes through the point (-3, 6) and has slope . 3 (34) Find the equation for the line that goes through the points (3, -1) and (1, -4) (35) Find the equation for the line that is parallel to 2x + 4y = 5, passing through (1, 2) (36) Find the equation for the line that is perpendicular to 6x – 3y = 18, passing through (4, -3). (37) Find the equation for the line shown on the graph. (b) y (28) Graph the lines: (a) 2x + 3y = 6 (38)Determine which of the following are functions and explain your answer. a) {(1, 2), (3, 6), (5, -1), (2, 3)} (b) {(1, 2), (3, 6), (5, -1), (3, 7)} (c) (d) (d) (39) Answer the following questions about the given graph. a) What is the domain? (b) Range (c) f (-2) (d) f (3) (e) y-intercept (f) x-intercept (40) f ( x) x2 3 Find: (a) the domain of the function (b) f (2) (c) f ( -2) 3x 2 (41) Find each root. (a) 4x 2 (b) 3 8a 3 (c) x 2 10 x 25 (d) 5 (2) 5 (42) Find each root. Assume that all variables represent positive real numbers. 8 1 8 (a) 144 (b) 3 (c) 4 (d) 36 x 6 y 12 x 27 81 o (43) Simplify. Assume all variables represent positive real numbers. 5x (a) 175a 2 b 3 (b) 3 16 x 12 y 4 (c) 4 (d) 16 z 4 (f) 8 xy (g) 1 (h) 2 1 2 (e) 50 2 9 x y (44) Multiply. Simplify the answers. Assume all variables represent positive numbers 3 x y (i) 5 3 3 52 (b) x( x 3) x 3 ( x 3) (c) 3 2 4 6 2 7 (d) 2 3 1 3 1 (e) (45) Simplify and combine like radicals. All variables represent positive numbers. (a) 4 2 x 6 2 x (b) 2 8 (c) 98 50 72 (46) Solve. (a) 5 x 6 2 (b) 6 x 1 2 7 (c) y 2 4 y (a) 3 52 3 3 18 2 3 17 (47)Solve using the principle of square roots. (a) 4x = 20 (b) y (c) x2 – 10x + 25 = 64 4 16 2 2 (48) Solve by completing the square. (a) x + 6x + 4 = 0 (b) 2 = x – 5x 2 2 (c) 9 – 3r = r (d) x + 10x – 7 = 0 (e) x2 – 2x – 17 = 0 2 (49)Solve the following by using the quadratic formula. (a) x2 – 3x + 2 = 0 (b) 6x2 – x – 1 = 0 x2 x 1 (c) 5x2 + 5x + 1 = 0 (d) (e) x 2 10 x 18 (f) x2 – 2x – 6 = 0 8 4 2 (50)Solve each of the following equations that are reducible to quadratic. (a) x 4 17 x 2 16 0 2 1 (b) 2(2 x 1) 2 7(2 x 1) 6 0 (c) 2 x 2 x 1 1 0 (d) a 3 2a 3 3 0 (e) 3x 4 x 1 0 (51) Mark’s workout consists of jogging for 3 miles, and then riding his bike for 5 miles at a speed 4 miles per hour faster than he jogs. If his total workout time is 1 hour, find his jogging speed and his biking speed. (52)Together, Noodles and Freckles eat a 50-lb bag of dog food in 30 days. Noodles by himself eats a 50-lb bag in 2 weeks less time that Freckles does by himself. How many days to the nearest whole day would a 50-lb bag of dog food last Freckles? (53) A whole number increased by its square is two more than twice itself. Find the number. (54) f ( x) ( x 2) 2 1 find: (a)vertex (b) axis of symmetry (c) x-intercepts (d) y-intercept (e) graph (55) The graph of f ( x) x 2 8 x 11 is just like the graph of f ( x) x 2 except it is shifted ______units to the ______________ and __________ units____________. (right or left) (up or down) Solutions 20 2 x (3)(a) 14x − 21 (b) 2x + 20 (4)(a) −3 (b) 0 (1)(a) 58 (b) 48 (2)(a) x 2x 5 (b) x 32 54 7 6 5 (c) 19 (d) (e) (f) 3 (5)(a) 4 (b) 4 (c) (d) (e) no solution (f) 15 3 5 5 19 2 S 2 r 3V A P (g) all real numbers (6) 3 (7) A (8) T (9) h (10) 4.5 m (11) 96 h PR 2 r 1 45 2 (12) one 16-inch pizza (13) 7 quarters, 14 nickels (14)(a) , (b) , (c) , 2 7 5 15 14 1 (d) , (e) , (15)(a) 2, (b) , 2 2, (c) , 3 4 11 3 3 2 5 4 3 (16) 12 x 12 x 9 x 2 (17) 12 y 3 y 13 y 11y (18) 5x (19) 2 x 3 8 x 2 19 x 2 (20)(a) 4 x 3 12 x 2 44 x (b) 15 x 2 37 xy 18 y 2 (c) 5 x 3 x 2 16 x 16 (d) 9 x 2 4 (22)(a) 5 xy x 2 3x 2 (b) x y 2x 1 (24)(a) x 5x 3 (b) 2t 8t 4 3 1 x x2 (23)(a) y 42 x (21)(a) 4 x 2 (f) 4 x 2 22 x 12 (e) 4 y 2 16 y 16 (c) 2 x 11x 9 (b) 2 x 2 3 x 4 (c) 6 x 1 (b) x 2 y 4 x 3 (d) 5x 33x 5 (e) x 8 1 x3 2 (f) 5x 35x 3 (g) y 2 9 y 3 y 3 (h) 6 xx 5x 4 (25)(a) 0, −2 7 (d) , 2 2 3p 1 p3 (28) (a) (e) 5 1 (f) 0, , 1 (26)(a) 3 x 1 (e) 3, 4 (27)(a) 12 (b) 1 (c) 3 (d) 3 (b) (b) y 8 y2 2 5 (b) 5, 7 (c) , 3 2 2 4y y 5 3 (c) (d) 2 t y 1 y 1 (e) no solution (c) (d) 3 8 y-int: (0, 2) x-int: , 0 4 3 (d) slope = 0 y-int: (0, -3) x-int: none 5 (30)(a) Perpendicular (b) neither (c) perpendicular (d) perpendicular (31) (32) y = -3x + 1 7 2 3 11 1 5 1 2 (33) y x 4 (34) y x (35) y x (36) y x 1 (37) y x 1 3 2 2 2 2 2 3 (38) (a) is a function (b) is not a function since 3 “goes to” 6 and to 7 (c) is a function (d) is not a function by the vertical line test. (39)(a) (∞, 1) U [3, ∞) (b) (∞, 3) U [4, ∞) (c) 1 (d) 4 1 1 2 (e) (0, 2) (f) (-1.5, 0) (40) (a) x | x , x (b) (c) (41)(a) 2| x | (b) 2a 8 4 3 2 1 (c) | x + 5 | (d) 2 (42) (a) does not exist in the real numbers (b) (c) x 2 (d) 6 x3 y6 3 3 3 4 2 2 xy 5x 6 6 (43)(a) 5ab 7b (b) 2 x 4 y 3 2 y (c) (d) (e) (f) (g) 2 1 2z 10 3 xy 2 y-int: (0, 2) x-int: (3, 0) 3 (c) slope is undefined, y-int: none, x-int: (4, 0) (29)(a) slope = (h) 10 3 2 4 (i) (b) slope = x 2 xy y (44)(a) 3 3 2 x y (b) 2 (45) (a) 10 2 x (b)x2(x + 3) (c) 4 2 (c) 24 3 6 14 (46) (a) 2 (d) 5 3 (e) 1 (b) 4 (c) 2 5 17 33 5 (c) 2 2 1 1 5 5 (d) − 5 4 2 (e) 1 3 2 (49)a) 2, 1 (b) , (c) (d) 1 5 (e) 5 7 3 2 10 1 1 1 (f) 1 7 (50)(a) 4, 4, 1, 1 (b) , (c) 2, 1 (d) 1, 27 (e) , 1 2 4 9 (51) Jogging: 6mph, biking: 10 mph (52) 68 days (53) 2 (54)(a) (−2, −1) (b) x = −2 (47)(a) 5 (b) (c) (−1, 0), (−3, 0) 3 17 4 (d) (0, 3) (c) 13, 3 (e) (48)(a) 3 5 (b) (55) 4 units right, 27 units down