Solve x^2 + 7x + 10 = 0

First factorise the quadratic into the form (x + a)(x + b) = 0.This will make x^2 + ax + bx + ab = 0.Work out a and b so that a + b = 7 and ab = 10.a = 5 b = 25+2 = 7 52 = 10.