Question

Dado o sistema de equacoes responda:

Answer 1

{3x-y=4
{x-y=8
x-y=8. (-3)
{3x-y=4
{-3x+3y=-24
2y=-20
y=-20/2
y=-10
x-y=8
x-(-10)=8
x+10=8
x=8-10
x=-2
x+y=-2+(-10)=-2-10=-12
letra E