Answer:
The answer to your question is: x = -7
Explanation:
Data
y - x = 9
10 + 2x = -2y
1.- Change the form of the equations
- x + y = 9 ---- (1)
2x + 2y = -10 ---- (2)
Solve equation by elimination
Multiply (1) by 2
- 2x + 2y = 18
2x + 2y = -10
0 4y = 8
y = 8/4
y = 2
Find the value of x (in equation 1)
- x + 2 = 9
- x = 9 - 2
- x = 7
x = -7