This week, I have learned what are non-permissible values and how to simplify rational expressions.

Non-permissible values are the values that x cannot be. The values are determined by the denominator; it’s the values that results in 0 as the denominator.

Let’s look at an example:

First step is to factor.

Once you factor everything out, list out the non-permissible values. After, you can simplify by crossing out what is common on the nominator and denominator which basically equals to one.

               

Let’s look at another example of multiplying and dividing rational expressions.

When it comes to dividing, we start by listing the given non-permissible values. The first one that we can see is 4.

Since it’s division, we must flip the second fraction (reciprocal) and then we can list the other non-permissible value which is 5. Next is to factor then list out any other given non-permissible values.

 

 

 

 

The other non-permissible value is -5. Now we can cancel out values diagonally which will give us the simplified expression.