Hi all,(adsbygoogle = window.adsbygoogle || []).push({});

I have a very simple issue, but can't get round of it.

I have a long sum of rational functions, which is in the form for example

[itex]\frac{n_{1}}{d_{1}}+\frac{n_{2}}{d_{1}}+\frac{n_{3}}{d_{1}}+\frac{n_{4}}{d_{1}}+\frac{n_{5}}{d_{2}}+\frac{n_{6}}{d_{2}}+\frac{n_{7}}{d_{1}\cdot d_{2}}+\frac{n_{8}}{d_{1}\cdot d_{2}}+\frac{n_{9}}{d_{1}\cdot d_{2}} [/itex]

and I would like to put it in the form

[itex]\frac{n_{1}+n_{2}+n_{3}+n_{4}}{d_{1}}+\frac{n_{5}+n_{6}}{d_{2}}+\frac{n_{7}+n_{8}+n_{9}}{d_{1}\cdot d_{2}} [/itex]

If I use Factor or Simplify it would just put all over one single denominator [itex]d_{1}\cdot d_{2} [/itex], taking also so much time since my expression is huge.

Any help?

Thanks

**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!

# Collecting denominators together with Mathematica

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