Question

resolver os sistemas

x+2y=0
3x+y=-5

Answer 1

Isolando X:
x+2y=0
x=2y

Substituindo X:
3(2y)+y=-5
6y+y=-5
7y=-5
y=-5/7

Substituindo Y:
x=2(-5/7)
x=-10/7

S={($- \frac{5}{7},-\frac{10}{7}$)}