Answer
D=(-$\infty$,-2) U (-2,2) U (2,5) U (5,$\infty$)
Work Step by Step
x$^3$-5x$^2$-4x+20$\ne$0
x$^2$(x-5)-4(x-5)$\ne$0
(x$^2$-4)(x-5)$\ne$
(x+2)(x-2)(x-5)$\ne$0
x$\ne$-2, 2, or 5
Therefore, the domain includes all real numbers except -2, 2, and 5.