ax^2 + bx + c
multiply the "a" and "c" coefficient
= ac
factor "ac" into a pair of numbers that adds to equal "b"
replace "bx" in the expression with factor pair
group terms and factor
* example problem:
2x^2 + 13x + 6
ac
2*6=12
factor pairs of 12
1*12 = 12
3*4=12
6*2=12
** The factor pair 1 and 12 add to make 13
replace 13x with (x+12x)
2x^2 + x + 12x + 6
group similar terms
(2x^2 + 12x) + (x + 6)
factor
2x(x + 6) + (x + 6)
The same parenthesis (x + 6) can be factored further by combining the outside multipliers 2x and 1
= (2x + 1)(x + 6)