Using the following quadratic equation, find x: x2 + 3x -4
x2 +3x -4. (x + a) (x - b) x has no co-efficient so each is 1 x. next find two numbers with a product of -4 and a sum of +3. cannot be 2,2 as these numbers have a sum of -4, 0 or +4 depending on whether they are positive or negative. so.. +4 and -1. (x+4)(x-1) x = -4 or +1
