# Factoring Limits

1. Dec 11, 2011

### PowerBuilder

Okay so I've been teaching myself (with the aid of the mighty internet & several friends) algebra & now calculus. I have found that I didn't do too good at high school for various reasons. Some good...some not good. Anyway...

I have a (what is probably a basic question) about factoring limit questions. I understand that with an equation like below (which results in 0, you need to factor it)

Lim x^2 -5x - 6
x->2 ------------
x^2 - 4

factored it works out to (x-3)(x-2).

I can manage that. What is the approach taken when you have something like

Lim x^2 + 3x -24
x->4 ------------
x^2 + 8

I don't know what to do in a situation like this, I don't know how to break it into a (x a)(x b) situation. I hope this thread isn't looked at & thought 'what a twit' I should say that I am aware of the quadratic equation............

2. Dec 11, 2011

### JHamm

In this problem you can actually just substitute $x = 4$ since the result is defined (no 0 in the denominator or an infinity anywhere) :)