Question

Find the domain of the rational expression: 6-x/4x+20


a.all real numbers except -20


b. all real numbers except -5


c. all real numbers except 6


d. all real numbers except 0

Answer 1

Interpreting the expression as (6 − x)/(4x + 20), the denominator cannot be 0:
4x + 20 = 0 → 4(x + 5) = 0 → x = −5.
So the domain is all real numbers except −5 — answer (b).