Solving this is no different than solving a regular equation, because you’re “undoing” what’s been done to the h.
Since the right side is pi•r^2•h, you need to cancel the pi and r^2 from the right with division, just like you would if it had be V = 7•h. Division “undoes” multiplication.
So you divide both side by pi and r^2 to get:
V ÷ (pi r^2) = h