How do you factor #6x^2 + 14x -12#?

2 Answers
May 17, 2015

This can be done by find its roots. Knowing its roots, you'll be able to factor your equation, as follows:

First, let's solve this using Bhaskara:

#(-14+-sqrt(14^2-4(6)(-12)))/(2*6)#
#(-14+-22)/12#

Roots:
#x=-3#, which is the same as the factor #x+3=0#
#x=2/3#, which is the same as the factor #3x-2=0#

Using these factors, we can rewrite the original function:

#6x^2+14x-12=2(3x^2+7x-6)=2(x+3)(3x-2)#

May 18, 2015

A Different Method.

The answer is #2(3x-2)(x+3)# .

Problem: Factor #6x^2+14x-12#

Factor out the GCF #2# .

#2(3x^2+7x-6)#

Factor #3x^2+7x-6#. The form of this equation is #ax^2+bx+c#.

Multiply #a*c#.

#3*-6=-18#

Determine two numbers that when added will equal #b#, or #7#, and when multiplied will equal #a*c#, or #-18#.

The numbers #9# and #-2# fit the pattern. Rewrite the equation with #9x# and #-2x# in place of #7x#.

#2(3x^2+9x-2x-6)#

Factor by grouping.

#2(3x^2+9x)-(2x-6)#

#2(3x(x+3)-2(x+3))#

Factor out the GCF #x+3# .

#(3x-2)(x+3)#

Complete answer:

#2(3x-2)(x+3)#