You are basically just adding, so combine like terms.
3x^2 + 5x^2 = 8x^2
6x - 2x = 4x
4 - 8 = -4
So the answer is D.
Distribute and combine like-terms!
-4x + 12x - 2x - 2
6x - 2
Safdsfghjklphuiyotrdtufchvjbkn;pp;lrsyketdgxvcb nmklj;pu8yutiyfgch bmhjkityfjhvyfug . =235678