Question

Substation
X=5
2x+y= -15

Answer 1

10+y=-15
y=-15-10
y=-25
Hope my answer helped!

Answer 2

$2(5) + y = - 15$

$10 + y = - 15$

Subtract 10 both sides

$y = - 25$

Solving for X

No need to you already got X.

Answer

(5,-25)