Question

Resolver o sistema
x-y=3
2x-2y=-4

Answer 1

2x = -4 + 2y simplifica por 2
x = -2 + y

2(-2 + y) -2y= -4
2y - 2y = 4 - 4
0 = 0

x = -2 + 0
x = -2
y = 0