Factor $4608=48^{2}\times 2$. Rewrite the square root of the product $\sqrt{48^{2}\times 2}$ as the product of square roots $\sqrt{48^{2}}\sqrt{2}$. Take the square root of $48^{2}$.
$$48\sqrt{2}=y$$
Swap sides so that all variable terms are on the left hand side.
