Step by step explanation

Answer:
[tex]\huge\boxed{\tt{x = -5 , y = 2}}[/tex]
Step-by-step explanation:
x = y - 7 ---------------------(1)
-y - 2x = 8 --------------------(2)
Put Equation (1) into (2)
- y - 2 ( y-7 ) = 8
-y - 2y + 14 = 8
-3y = 8 - 14
-3y = -6
Divide -3 to both sides
y = -6 / -3
y = 2
Put y = 2 in (1)
x = 2 - 7
x = -5
So,
x = -5 , y = 2
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!