Question

2x + y = -2

x + y = 5

The x-coordinate of the solution to the system shown is _____.

Answer 1

The x-coordinate of the solution to the system shown is -7.

Proof:
From the 2nd equation, equate in terms of y:
y = 5 - x
Then substitute it to the first equation:
2x + 5 - x = -2
2x - x = -2 -5
x = -7