Answer:
A) -128x^8 - 384x^7
Explanation:
The pattern is each term is multiplied by -2x which means by the eighth term youll have 8 x's in the first and 7 in the second. As you started off with a positive and multiplied it an even amount of time you'd end up with a negative answer. Think of it like this, it switches with each multiple so it would go: Positive, negative, positive, negative, this will get you a negative in the eighth term.
I know my explanation is a bit bad! I apologize!