Cross multiply ...(adsbygoogle = window.adsbygoogle || []).push({});

and then multiply by the common denominator...

how do you do it

do you do it in your head..by cross multiplying

or the other way

It seems like cross multiplying is less formal ...and I dont know if its 'right' to take the shortcut --since you have to do this so much

If you have more than two like with a partial fractions problem ...im obviously going to just mult/divide by the common denominator

But how do you do it in general ...

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How do you add Rational Expressions when youre in University Math?

**Physics Forums | Science Articles, Homework Help, Discussion**