Exercise algebra.manipulation.rational.simplify

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

Derivation

((x-2)*(x-1)+(x+1)*(-x-2))/((x+1)*(x-2))

⇒ algebra.equations.linear.distr-times

(x^2-3*x+2-x^2-3*x-2)/((x+1)*(x-2))

⇒ algebra.equations.linear.merge

-6*x/((x+1)*(x-2))