Question

qual a equação de 2x+3y=-9 2x-2y=-1

Answer 1

{2x+3y=-9
{2x-2y=-1 . (-1)

{2x+3y=-9
{-2x+2y=1

Corta os Xs

5y=-8
y=-8/5

2x+3y=-9
2x+3.(-8/5)=-9
2x-24/5=-9
10x/5-24/5=-45/5

Corta os 5s

10x-24=-45
10x=-45+24
10x=-21
x=-21/10