Exercise algebra.manipulation.rational.simplify

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

Derivation

((x-2)*6-(x-1)*3)/((x-1)*(x-2))
algebra.equations.linear.distr-times
(6*x-12-3*x+3)/((x-1)*(x-2))
algebra.equations.linear.merge
(3*x-9)/((x-1)*(x-2))