Answer
$x^3 + 3x^2+3x+1$
Work Step by Step
RECALL:
The formula for the cube of a binomial $a+b$ is
$(a+b)^3=a^3+3a^2b+3ab^2+b^3$
Use the formula above with $a=x$ and $b=1$ to obtain:
$(x+1)^3
\\= x^3 + 3(x^2)(1) + 3(x)(1^2) + 1^3
\\x^3 + 3x^2+3x+1$
