Answer
$$h=\frac{3V}{lw}$$
Work Step by Step
$$V =\frac{1}{3}lwh$$
To solve for $h$, it must be isolated on one side.
Multiply both sides by $3$.
$$V(3) =(\frac{1}{3}lwh)(3)$$ $$3V =lwh$$
Divide both sides by $lw$.
$$\frac{3V}{lw} =\frac{lwh}{lw}$$
$$h=\frac{3V}{lw}$$