# Week 16 Blog Post

This week I learned: when you simplify the expression, you need to find the non-permissible value first and divide the numerators and denominators by their common factors. And then multiply the numerators, multiply the denominators.

For example:

$\frac{c}{10} \div \frac{5d}{2c}$

=$latex \frac{5dc}{20c} =$latex \frac{4}{d}

the non-permissible value is c/=0