Simplify and list any necessary restrictions

Question

R(x) = (x^2+x-20)/(x^2-6x+8)

Answer 1

Factor numerator and denominator: R(x)=(x+5)(x-4)/(x-4)(x-2) cancel the (x-4)'s to get R(x)=(x+5)/(x-2) x cannot = 2 or 4, as the denominator cannot = 0