Answer
$\color{blue}{b(b^2+9b+27)}$
Work Step by Step
With $27=3^3$, the given polynomial is equivalent to:
$=(b+3)^3-3^3$
Factor using the formula $a^3-b^3=(a-b)(a^2+ab+b^2)$ with $a=b+3$ and $b=3$ to obtain:
$=(b+3-3)[(b+3)^2+(b+3)(3) + 3^2]
\\=(b+0)[(b^2+6b+9)+3b+9+9]
\\=b(b^2+6b+9+3b+18)
\\=\color{blue}{b(b^2+9b+27)}$
