Question

Resolva o sistema de equação a seguir
x-y = 5
2x + 4y = -2

Answer 1

7 - 2 = 5

2 x (-1) + 4 x 0 
-2 + 0 = -2

Answer 2

{x-y=5 --> x=5+y
{2x+4y=-2

2(5+y)+4y+2=0
10+2y+4y+2=0
12+6y=0
6Y=-12
Y=-12/6
Y=-2

•X=5+y•
x=5+(-2)
x=5-2
x=3