Answer
$3y^3+2y^2+y$
Work Step by Step
We divide each term of the polynomial by the monomial as follows
$$
(18y^3 + 12y^2 + 6y) \div 6=\frac{18y^3 + 12y^2 + 6y}{6}
\\ =\frac{18y^3 }{6}+\frac{ 12y^2 }{6}+\frac{ 6y}{6}\\
=3y^3+2y^2+y
.
$$