Can someone answer this question and make sure they show working out. Will reward brainliest to the best answer.

Answer:
8a²+8a+12b = 8a²+8a+12b
Step-by-step explanation:
first, expand the brackets
4a + 4a + 12a² + 8b + 4b - 4a²
then, collect like terms
8a + 8a² + 12b
then, rearrange
8a² + 8a + 12b