The correct answer is D .
A is incorrect because the original expression has numbers next to a parenthesis . Which means that you have to multiply .
5(x+8) + 6(x-3)+10(x+4)
5x + 40 + 6x+ -18 + 10x+40
The answer is not C because it's not positive 18 . It's -18.
6x-18=6x+-18
