I almost have the answer but I can't quite get there.
Differential equation is
dH/dt= (40-H)^2/100
I solved it through here:
H= 40 - 200/(2t + 5)
However, when I plug in a value t=5 I get the wrong answer. My professor has this but the following step says:
H=80t/(2t+5)
How do I get to that?