Please, post the instructions along with your question, and if possible share the question in symbolic form, not in words.
Do you mean Question #5? By (2) x cube, do you mean 2x^3?
I strongly suggest that you use lots of parentheses ( ) to show how your numbers are grouped, and not to use " x " to denote multiplication (use " * " for that, please.
If only you'll clear this up, I'd be happy to help.
I will assume that your post is 2x^3 - 3(9x-5)^2.
Then 2x^3 - 3(81x - 90x + 25). Does this have any resemblance to what you wanted me to see in your post?