Solve for h.....

h^4+1440000 = 2500 h^2         rearrange as

h^4 - 2500h^2 + 1440000  = 0       factor as

( h^2 - 1600) (h^2 - 900)  =  0

(h + 40) (h - 40) (h + 30) (h - 30)   = 0 

Setting each factor to 0   we have have that  h = ± 40   or h = ± 30

We are dealing with a complex problem runing throught the calculator we get

-40,40,-30,30

Those are the facts but the real answer will be debaled bettween the 40's and 30's

So try both if you can other wise theres a problem with the question

Hope this was helpfull