Why are you looking for a solution centered at x_0=1.
I did x_0=0 instead. I think it is easier.
Remember you need to find the "Cauchy Product"
I actually don't understund what you mean by x_0=1 but I have to say that I did my half-done solution using my math book which uses the same approach. Although it is hard to figure out what the all solution means pictorially because the author of this book tried to explain the examples as briefly as possible.
I analyzed your solution and have to admit that I can't understand, how you get 3a3-b2=1.
How does the final answer look like ?
I am little bit confused.