Page 32

messersmith_power_introductory_algebra_1e_ch4_7_10

66) Given the following system of equations, 2x y 9 2x y c fi nd c so that the system has a) an infi nite number of solutions. 9 b) no solution. c can be any real number except 9. 67) Given the following system of equations, 9x 12y 15 ax 4y 5 fi nd a so that the system has a) an infi nite number of solutions. 3 b) exactly one solution. a can be any real number except 3. 68) Given the following system of equations, 2x 7y 3 4x by 6 fi nd b so that the system has a) an infi nite number of solutions. 14 b) exactly one solution. b can be any real number except 14. Extension Let a, b, and c represent nonzero constants. Solve each system for x and y. 69) 5x 4by 6 2 2 70) ax 6y 4 16 a, b a 5x 3by 8 5 b ax 9y 2 71) 3ax by 4 72) 2ax by c a 1 4a , 19 4b b a ax by 5 ax 3by 4c a , 2b c 5a , 7c 5b b Objective 3: Use the Elimination Method Twice to Solve a Linear System Solve each system using the elimination method twice. 57) 4x 5y6 3x 8y 15 58) 8x 4y21 5x 6y 12 a 59) 4x 9y 7 6x 11y14 60) 10x 3y 18 9x 4y 5 123 17 , 78 17 b a 39 14 , 9 28 b a 203 10 , 49 5 b a87 67 , 112 67 b Find k so that the given ordered pair is a solution of the given system. 61) x ky 17; (5, 4) 3 2x 3y2 62) kx y13; (1, 8) 5 9x 2y 7 63) 3x 4y9; (7, 3) 8 kx 5y 41 64) 4x 3y7; (2, 5) 2 3x ky 16 65) Given the following system of equations, x y 5 x y c fi nd c so that the system has a) an infi nite number of solutions. 5 b) no solution. c can be any real number except 5. need to do before you add the two equations together? R3) Are there any problems you could not do? If so, write them down or circle them and ask your instructor for help. R1) In this chapter, you have learned three methods for fi nding the intersection of two lines. Which of the three methods do you prefer and why? R2) Suppose you want to eliminate the y-values in a system of linear equations. What do you 270 CHAPTER 4 Linear Equations and Inequalities in Two Variables www.mhhe.com/messersmith


messersmith_power_introductory_algebra_1e_ch4_7_10
To see the actual publication please follow the link above