You can put this solution on YOUR website! If P(x) = 4x^2+2x-7
and you are asked
then put your R = and your P = into the problem and solve.
(2x^2+5x-3) - (4x^2+2x-7)
This can be carried on to solve and get answer to x but you didn't ask for that. If you need to you can factor using foil or the quadratic formula.