Please help me solve S=2(pie)rh+2(pie)r squared, for h

Question

Please help me solve this.

Answer 1

S = 2pi(rh) + 2pi (r^2)

subtract 2pi(r^2) from both sides

S - 2pi(r^2) = 2pi(rh)

since the right is all multiplication, you can divide by all pieces at the same time.  so divide both sides by 2pi(r)

then h = S/[2pi(r)] - [2pi(r^2)]/[2pi(r)]

simplifying gives h = S/[2pi(r)] - r