#### Answer

$y=\pm\sqrt{6}$

#### Work Step by Step

Since $x^2=a$ implies $x=\pm\sqrt{a}$ (the Square Root Principle), the solutions to the given equation, $
5y^2=30
,$ are
\begin{array}{l}\require{cancel}
y^2=\dfrac{30}{5}
\\\\
y^2=6
\\\\
y=\pm\sqrt{6}
.\end{array}