if:

V= (6-(r^2)/(3))*h and (h/(2-r)) = 5/2

write v as a function of h. Simplify the function so that you can express it as a polynomial in h.

I think you have to find what r^2 is...and then plug it in or something? although that doesnt seem to be working for me, however it may be because im doing that wrong as well.....can anyone help?