for the expansion, you need to first square (2+h) which is just h^2 + 4h + 4 (if you need more explanation for this please reply and say so), then you are subtracting 4 so you are left with h^2 + 4h.

you can still make this answer simpler if you want by dividing it:

you are dividing by h and so 4h/h is just 4, and h^2/h is just h, so your final answer is h + 4