This week in pre-calculus 11, we had our graphing test then got straight to work on our next chapter: Rational Expressions. We started off by reviewing basic factoring that we’ve been doing for the past couple years. Then following our review, we started learned about multiplying, dividing, adding and subtracting rational expressions. I found this, for the most part, quite self explanatory. The non-permissible values are the numbers you cannot use in the bottom of the fraction. They cannot be used in the bottom of the fraction because it will equal 0 and as we have learned, we cannot have a 0 on the bottom of a fraction. For example:

This question asks to determine the non-permissible values for this rational expression.

First you have to factor to find the non-permissible values. The factored version of this equation.

After you have factored what you can, then you can find the non-permissible values. In this case, x cannot equal 5, or -4.

Thank you for reading, hope you’ve learned something!