#### Answer

(1) $-(5a^3+2a-17)$
(2) $-5a^3-2a+17$

#### Work Step by Step

Two expressions equivalent to the opposite of a polynomial can be found by:
(1) taking the negative of the polynomial; and
(2) changing the sign of each term of the polynomial
Thus, two expressions equivalent to the opposite of the given polynomial are:
(1) $-(5a^3+2a-17)$
(2) $-5a^3-2a+17$