Answer:
4x
Explanation:
We have 6x + -2x, the negative is trying to throw us off here.
Usually it would be one sign to combine like terms, but this has 2. Do keep in mind that the "-" sign belongs to 2x. Therefore it's more like 6x + (-2x).
Since the negative is there, we can just switch the equation to a subtraction problem.
6x - 2x
4x