A3. Which of the following expressions has a non-negative value for $x=5$?
(A) $-x^{3}+x$
(B) $x^{3}-x$
(C) $-x^{2}+x+12$
(D) $-x^{2}+17$
(E) $2 x-20$
A3. For $x=5$ the expression $x^{3}-x$ has a non-negative value, and specifically $x^{3}-x=5^{3}-5=125-5=120$.