begin{equation}
begin{aligned}
f(h) = pi h^3 -9pi h^2 +90\
f'(h) = 3pi h^2 -18pi h\
h_{n+1} = h_n-frac{f(h_n)}{f'(h_n)}\
h_{n+1} = h_n - frac{pi h_n^3 -9pi h_n^2 +90}{3pi h_n^2 -18pi h_n}\
h_{n+1} = frac{3pi h_n^3 - 18pi h_n^2 - pi h_n^3 -9pi h_n^2 +9}{3pi h_n^2 -18pi h_n}\
h_{n+1} = frac{2pi h_n^3-9pi h_n^2-90}{3pi h_n^2-18pi h}
end{aligned}
end{equation}