Solve: Combining Like Terms in (+3x) + (-3x)

Firstly, we will draw a number line and label 3$x$ on it.

Since we have -3$x$ in parentheses, we need to move 3 steps to the left on the number line:

Remember the rule:

$+(-x)=-$

Therefore, we can write the exercise as follows:

$3x-3x=0$