Answer:
x = -1
y = -7
Explanation:
y=9x+2`
-2x+7y=-47 ==> isolate y
Equation 1: 7y = 2x - 47 ==> add 2x on both sides
Equation 2: y = 9x + 2
7 * (y = 9x + 2)
Equation 3: 7y = 63x + 14
Equation 1: 7y = 2x - 47
Subtract equation 1 from equation 3:
7y = 63x + 14
- (7y = 2x - 47)
7y-7y = 63x-2x + 14-(-47)
0 = 61x + 14 + 47
0 = 61x + 61 ==> solve for x
-61 = 61x ==> subtract 61 on both sides to isolate x
x = -1
Now solve for y
y = 9(-1) + 2 ==> plugin -1 for x in y=9x+2`
y = -9 + 2 ==> simplify
y = -7
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