1. solve the system by the elimination method. check your work. r - 9s = 2 3r - 3s = -10 {(-4, -8/3)} {(-4, -3/2)} {(-4, -2/3)}

R - 9S = 2 (1) 
3R - 3S = -10 (2)

(1)x 3
3R - 27S = 6 (1a)

(1a) - (2):
-3s - ( -27s) = -10 - 6
- 3s + 27s = -16
24s = -16
s = -2/3 sub into (1)
R - 9(-2/3) = 2
R + 6 = 2
R = 2 - 6
R = -4

Ans: R = -4, S = -2/3 [ (-4, -2/3) ]

The correct answer for R and S are
R = - 4
S = - 2/3

( -4, - 2/3)

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