Simplify each expression.

-x + x

- (a + b) + (a + b)

0

Step-by-step explanation:

-x + x - (a + b) + (a + b)

Distribute the negative sign into (a + b).

-x + x - a - b + a + b

Notice how each term has itself and an opposite (For example x and - x)

These terms add up to zero.

Thus, when all of the terms are added up, the result is 0.