Solving for "g" in the Gordon growth model (reading 42)

How do you solve for growth in the Gordon constant growth model? This is an algebraic question. I’m trying to flip Po = Do(1+g)/(r-g), to solve for g. I’m stumped!

expand it P0*r - Po*g = D0 + do*g now take g together (d0+p0)*g = Po*r - D0 g = (p0*r-D0)/(d0+p0)