Promise no more questions today! ^_^

The reason I'm stuck on these is because I've completely forgotten what im doing, after returning to these from months ago.

I need to:

1) Express in the form where "a" and "b" are the numbers to be found.

This is what I've got thus far:

Then I need to plot for the original equation. Not alot

2) Expand the following using Pascal's Triangle

I could manage the expansion but not sure how to go about this one.

Thanks