Page 23

messersmith_power_introductory_algebra_1e_ch4_7_10

c) Solve the system of equations using the substitution method, and explain the meaning of the solution. d) Graph the system of equations, and explain when it is cheaper to rent a cargo trailer from A and when it is cheaper to rent it from Rock Bottom Rental. When is the cost the same? 56) To rent a pressure washer, Walsh Rentals charges $16.00 per hour while Discount Company charges $24.00 plus $12.00 per hour. Let x the number of hours, and let y the cost of the rental. The cost of renting a pressure washer from each company can be expressed with the following equations: Walsh Rentals:  y 16.00x Discount Company:  y 12.00x 24 a) How much would it cost to rent a pressure washer from each company if it would be used for 4 hours? Walsh: $64.00; Discount: $72.00 b) How much would it cost to rent a pressure washer from each company if it would be rented for 9 hours? Walsh: $144.00; Discount: $132.00 c) Solve the system of equations using the substitution method, and explain the meaning of the solution. d) Graph the system of equations, and explain when it is cheaper to rent a pressure washer from Walsh and when it is cheaper to rent it from Discount. When is the cost the same? Solve by substitution. Begin by combining like terms. 49) 8 2(3x 5) 7x 6y 16 9(y 2) 5x 13y 4 (6, 4) 50) 3 4(2y 9) 5x 2y 8 3(x 3) 4(2y 1) 2x 4 (7, 1) 51) 10(x 3) 7(y 4) 2(4x 3y) 3 10 3(2x 1) 5y 3y 7x 9 (4, 9) 52) 7x 3(y 2) 7y 6x 1 18 2(x y) 4(x 2) 5y (5, 0) 53) (y 3) 5(2x 1) 7x x 12 8(y 2) 6(2 y) (0, 8) 54) 9y 4(2y 3) 2(4x 1) 1 a 16 5(2x 3) 2(4 y) , 6b 2 55) Jamari wants to rent a cargo trailer to move his son into an apartment when he returns to college. A Rental charges $0.60 per mile while Rock Bottom Rental charges $70 plus $0.25 per mile. Let x the number of miles driven, and let y the cost of the rental. The cost of renting a cargo trailer from each company can be expressed with the following equations: A Rental:  y 0.60x Rock Bottom Rental:  y 0.25x 70 a) How much would it cost Jamari to rent a cargo trailer from each company if he will drive a total of 160 miles? A: $96.00; Rock Bottom: $110.00 b) How much would it cost Jamari to rent a trailer from each company if he planned to drive 300 miles? A: $180.00; Rock Bottom: $145.00 is true, what does this mean? What does it mean if your fi nal statement is false? R3) Which exercises do you need to ask for help on in class? R1) So far, this chapter has demonstrated two methods for fi nding the intersection of two lines. Which method is easier for you? R2) Suppose you are using the substitution method and the variables drop out. If your fi nal statement www.mhhe.com/messersmith SECTION 4.2 Solving Systems by the Substitution Method 261


messersmith_power_introductory_algebra_1e_ch4_7_10
To see the actual publication please follow the link above