Simplifying
2y + -1y + -1y + x = -13

Reorder the terms:
x + 2y + -1y + -1y = -13

Combine like terms: 2y + -1y = 1y
x + 1y + -1y = -13

Combine like terms: 1y + -1y = 0
x + 0 = -13
x = -13

Solving
x = -13

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Simplifying
x = -13