Question

no sistema (x+y=-10 2x-6y=-36​

Answer 1

x+y=-10 ×(-2)

2x-6y=-36

-2x-2y=+20

2x-6y=-36

-8y=-16

y=-16/-8=2

x+y=-10

x+2=-10

x=-10-2

x=-12

Confere:

x+y=-10

-12+2=-10

-10=-10

Answer 2

x + y = - 10         ⇒  x = - y - 10

2x - 6y = - 36

2( - y - 10 ) - 6y = - 36

- 2y - 20 - 6y = - 36

- 8y - 20 = - 36

8y = - 20 + 36

8y = 16

y = 16/8

y = 2

x = - y - 10

x = - 2 - 10

x = - 12

Resposta: ( - 12, 2 ).