In order to solve this you need to factor the denominator.
x^2 +4x - 12
I see that 12 is a product of 6 and 2 and 4 and 3 and 1 and 12.
I pick the two products that, when added together, give me the 4x term.
Here it's 6 and two I just need to make one of them a negative.
now put them in this form:
(x + 6)(x-2)
In the fraction I see that there is an x-2 in the numerator. This can cancel out with the x-2 in the denominator. Now you have 1/x-6 but remember you can never have a zero in the denominator so x can't equal -6.
And you're done!
