For this case we have the following expression:
8x {[(7 + 4) x ^ 2] - [(11-7) x ^ 4]}
First, we solve the parentheses:
8x {[(11) x ^ 2] - [(4) x ^ 4]}
We now resolve the brackets:
8x {[11x ^ 2] - [4x ^ 4]}
We now solve the keys:
8x {11x ^ 2 - 4x ^ 4}
We apply the distributive property:

Answer:
