This week in Math 11 we learned how to simplify rational expressions. We do this by cancelling out what is equivalent. The first thing we do is figure out our non-permissible values, these are values that we cannot use because if we do our denominator will equal 0 and a math rule is that we can’t have a 0 in our denominator. Then we use the different math skills we have learned to first simplify the numerator and denominator, then once everything is simplified then we can cancel out what is the same or something common.

Example:

- right now due to the way our equation is written we can’t say what our non-permissible values are
- so first thing we can do is factor

- now that it is factored we can see that x cannot equal -9 and 9 because our rule is that we cannot have a zero inn our denominator and we we use those numbers as x’s we will get a zero

- we see that we can something in the numerator and denominator which is the (x+9)
- so we would cancel both of those out and be left with our final answer because we cannot reduce anymore

And as our final answer we would have our simplified expression and what our non-permissible values are.

x cannot equal -9 and 9