Exercise algebra.manipulation.rational.simplify
Description
simplify a rational expression (with a variable in a divisor)
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
4/(3*a)-2/(5*b)
⇒ algebra.equations.rational.rational-scale20*b/(15*a*b)-6*a/(15*a*b)
⇒ algebra.equations.rational.rational-plus(20*b-6*a)/(15*a*b)