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)
2/(7*x)-1/(4*x)
⇒ algebra.equations.rational.rational-scale8/(28*x)-7/(28*x)
⇒ algebra.equations.rational.rational-plus1/(28*x)