Given that , where is a polynomial.

State the degree of and find the value of and of .

(I am able to deduce the degree i.e. 3

I am also able to find the value of a ,i.e -2 and the value of b, i.e. 1.)

However, the following question linked to the above is what I am not able to solve:

Find also the remainder when is divided by .

(The answer given is -5.)