Question

Jack knows the surface area of a cylinder and its radius. He wants to find the cylinder's height. He needs to rewrite the formula A=2r(r+h) to find the cylinder's height (h) in terms of the cylinder’s surface area (A) and its radius (r). Which is the correct formula?

Answer 1

A=2r(r+h)
(A/2r)=r+h
(A/2r)-r=h

h=(A/2r)-r
or
h=(A-r^2)/2r