Question

How woule I solve 2x^2 + 4x - 30 = 0 ?

Answer 1

(2x - a ) ( x + b)

2b - a = 4
ab = 30

Answer 2

divide by 2 first gives x^2+2x-15=0
now get two factore that when multiplied you get 15 yet when added you get +2
5 and -3
use them to form (x+5)(x-3)=0
now seperate brackets
x+5=0,gives x=-5
x-3=0 gives x=3