Evaluating Limits: Understanding the Solution to a Challenging Calculus Problem

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Hello, I am struggling with limits in my calculus course and would appreciate a bit of help. The question is:

\lim_{x→-6}\frac{x^2-8x+12}{x^2-x+30}
So far I have tried the factoring and substitution methods but have not managed to match the answers given by online equation solvers. For example, when using direct substitution I get an answer of 4/3, whereas mathway (online solver) says the answer is x2-8x+12. Would someone please explain how that answer is possible? I've looked around online but nothing I've found seems to help in my understanding.
 
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NoLimits said:
Hello, I am struggling with limits in my calculus course and would appreciate a bit of help. The question is:

\lim_{x→-6}\frac{x^2-8x+12}{x^2-x+30}
So far I have tried the factoring and substitution methods but have not managed to match the answers given by online equation solvers. For example, when using direct substitution I get an answer of 4/3, whereas mathway (online solver) says the answer is x2-8x+12. Would someone please explain how that answer is possible? I've looked around online but nothing I've found seems to help in my understanding.
I get a limit of 4/3 as well. There's no way that I can see that the limit could be what you say mathway gives.
 
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Thanks, I was driving myself crazy trying to figure out what I did wrong.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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