Question

Resolva os sistemas
{ 2×+y=-10
×+y=5

Answer 1

2x + y = -10  * (-1)
x  +  y = 5

-2x - y = 10
x + y = 5

-x = 15 * (-1)
x = -15

x + y = 5
-15 + y = 5
y = 5 + 15
y = 20

Resposta: x = -15 e y = 20.