Question

x-y=11
2x-y=7
e essa ?

Answer 1

Explicação passo-a-passo:

$\left \{ {{x-y=11} \atop {2x -y=7}} \right.$

$\left \{ {{x-y=11}(-1) \atop {2x-y=7}} \right.$

$\left \{ {{-x +y=-11} \atop {2x -y=7}} \right.$

x = -5

2.(-5) -y = 7

-10 -y = 7

-y = 10 +7

-y = 17 (-1)

y = -17