Answer:
8x
Explanation:
3x + 8x are like terms which means they have the exact same variable.
To add like terms we add the coefficients which are 3 and 5.
3 + 5 = 8
We have 8 x's. So 3x + 5x = 8x.
In order to add terms, the variable part has to be exactly the same.
It's like saying 3 balls + 5 balls = 8 balls.