Week 16 in Precalculus

This week in Precalc 11 we learned how to multiply and divide rational expressions.  The General rule for doing this is:

1. Factor (numerator and denominator)

2. Use exponent laws

3. Cancel out like terms

this process is much like cross multiplying, for example:

 

since these fractions can get pretty long and “ugly”, writing them out is helpful and easier to manage. If you follow the 3 main rules as well than solving is much more efficient.

Monomials are easier because you can combine the numerators and denominators than simplify.

 

When it is a single variable expression you must factor in order to simplify. You can only cancel out EXACT terms. The + or – signs act as unpenatratable glue. They connect the numbers on either side of the sign, acting as a package.

To cancel out you can use the cross multiplication technique. Then combine the leftover numerators and denominators.

 

The last thing you must do, which you actually do first, is find the non-permissible values. A non-permissible value is the numbers which make the denominators equal to zero. You find these once you have factored.