You really might've mean to include several terms as the numerator, meaning
The work done on paper was very very lengthy. One would go with
Raising to higher terms, comparing corresponding parts after simplification would indicate values:
And you would want to see that whole process, but like said, very lengthy set of steps on paper, and so very likely to make type-written mistakes on attempt to put the solution process here.
You will be able to substitute the values to show
You lost one partial expression because of the A=0 and B=0.