Exercise algebra.manipulation.rational.simplify

Description
simplify a rational expression (with a variable in a divisor)

Derivation

((x+1)*7-(x-3)*2)/((x-3)*(x+1))
algebra.equations.linear.distr-times
(7*x+7-2*x+6)/((x-3)*(x+1))
algebra.equations.linear.merge
(5*x+13)/((x-3)*(x+1))