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)
(a^2-2*a-15)/((a+3)*(a-6))
⇒ algebra.equations.quadratic.nice-factors(a+3)*(a-5)/((a+3)*(a-6))
⇒ algebra.equations.rational.cancel-div, clipboard=[condition == (a /= -3)](a-5)/(a-6)