Binomial Theorem problem!

Hey,

Doing homework, and came across this question. I cannot for the life of me figure out what I am doing wrong, but it doesn't match up to the answer at the back of the book. It does on wolfram alpha. So am I doing this correctly?

**Question:**

Find the first five terms in the expansion of each of the following:

b)

**My attempted answer:** ***I do not know how to show combinations using Latex, so hopefully this makes sense. Example: is "8 choose 0"***

**First Term:**

**Second Term**:

**Third Term:**

**Fourth Term:**

**Fifth Term:**

Answer at back of book:

Wolfram alpha: http://www.wolframalpha.com/input/?i=%282a+%2B+%283a^%28-2%29%29%29^8