x^3 + 4x^2 - 3x - 2 = 0

by quick tries of x = ±1, ± 2,

it shows on the first try that x = 1 is a solution
so x-1 must be a factor

do either long algebraic or synthetic division to show

x^3 + 4x^2 - 3x - 2
= (x-1)(x^2 + 5x + 2)

use the quadratic formula to find the other two roots.