How do you factor 6x^3+34x^2-12x6x3+34x212x?

1 Answer
Oct 9, 2015

2x(3x-1)(1x+6)2x(3x1)(1x+6)

Explanation:

Given
color(white)("XXX")6x^3+34x^2-12xXXX6x3+34x212x

First extract the obvious common factor of (2x)(2x) from each term:
color(white)("XXX")(2x)(3x^2+17x-6)XXX(2x)(3x2+17x6)

In the hopes of finding integer coefficient factors of (3x^2+17x-6)(3x2+17x6)
we consider the integer factors of 33 and of (-6)(6)
looking for a combination that will give us a sum of products =17=17

There are only a few possibilities. The diagram below might help understand the process:
enter image source here
The "working" combination is (3x-1)(1x+6)(3x1)(1x+6)

Which gives us the complete factorization:
color(white)("XXX")6x^3+34x^2-12xXXX6x3+34x212x
color(white)("XXXXXXXXXXX")=(2x)(3x-1)(1x+6)XXXXXXXXXXX=(2x)(3x1)(1x+6)