Answer
$$y=9$$
Work Step by Step
$\log_3y+3\log_3{y^2}=14$
Expressing the left side as the base-3 log of a single expression:
$\log_3({y\times ({y^2})^3)}=14$
Simplifying the left side:
$\log_3 {y^7}=14$
Raising 3 to both sides of the equation:
$y^7=3^{14}$
Solving for $y$:
$y=({3^{14}})^{\frac{1}{7}}=3^2=9$
