Answer
$(-3)^3+3(-3)^2-(-3)-3=0$
$-27+27+3-3=0$
$0=0$
$(-1)^3+3(-1)^2-(-1)-3=0$
$-1+3+1-3=0$
$0=0$
$(1)^3+3(1)^2-(1)-3=0$
$1+3-1-3=0$
$0=0$
Work Step by Step
$x^3+3x^2-x-3=0$
When graphing, the $x$-intercepts are $-3$, $-1$, and $1$. Simply plug these values into the equation to check the solutions.
$(-3)^3+3(-3)^2-(-3)-3=0$
$-27+27+3-3=0$
$0=0$
$(-1)^3+3(-1)^2-(-1)-3=0$
$-1+3+1-3=0$
$0=0$
$(1)^3+3(1)^2-(1)-3=0$
$1+3-1-3=0$
$0=0$
