Question

in relational fractions in one variable x , when the rational fraction is simplified , i am asked when the simplified rational fraction is defined , what will be the answer , is it that the dinominator must be different from zero or the common factor different from zero

Answer 1

for example , the simplifiction of {(x+5)^2-(5x-4)^2}/(36x^2-1) is (9-4x)/(6x-1) when is the simplified expression defined ? this is the question