Question

x + y = 9
x + 2y = 6

Answer 1

x vale 12 e y vale -3

Answer 2

x + y = 9 (-2)
x + 2y = 6

-2x - 2y = -18
x + 2y = 6
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-x = -12 .( -1)
x = 12

x + 2y = 6
12 + 2y = 6
2y = 6 - 12
2y = -6
y = -6/2
y = -3

X = 12
Y = -3

s={ 12, -3 }