Question

{x-y=-1
{2x+y=7 nao consigor resolver essa equaçao

Answer 1

{x-y= -1
{2x+y= 7

{x= -1+y
{2x+y= 7

2(-1+y)+y = 7
-2+2y+y= 7
3y= 7+2
3y= 9
y=3


2x+3= 7
2x= 7-3
2x= 4
x= 2