May 19th 2018 archive

Week 14 – Multiplying and Dividing Rational Expressions

This week we learned how to multiply and divide rational expressions, which are much simpler than adding and subtracting.

It’s easiest to explain how to do the question as an example so,

e.x. \frac{x+2}{(x-4)(x+3)}*\frac{3(x-4)}{2x(x+2)}

When multiplying and dividing, you can cancel out expressions that are in both the numerator and denominator. In this case: (x+2) and (x-4)

After doing this, your equation should look like \frac{3}{2x(x+3)}

Because you can’t factor the expression anymore, that’s as far as it can be simplified.

Another thing to always do with expressions is label your restrictions. In this case, the restrictions are number that can’t be used in the place of variable “x” that would cause the denominator to become 0.

For this equation x cannot equal 4, -3, 0, -2