Answer
$-3, -1, 3/2$
Work Step by Step
This question asks for ALL zeros of the function
Given $P(x) = 2x^3 + 5x^2 - 6x - 9$
See image below for synthetic division
So x = -1 is a zero
Factor and set P(x) = 0
$2x^2 + 3x - 9$
$(2x - 3) (x +3)$
$x = 3/2, -3$
Thus the solutions are $-3, -1, 3/2$