Rational expressions are fractions that have a polynomial in the numerator or ... The first step insimplifying a rational expression is to determine the domain, the ... So we need to figure out what values of the variable(s) in the expression ... The domain is all x not equal to -9 or 1. .... x3 – x2 – 20x = 0 ... x = 0 or x = 5 or x = -4.
