Easy math question please help

if you have -10h + h^2 divided by h if you cancel out the h on the bottom do you get -10 + h^2 or -10 + h.

I havnt done math in years and would also like to know if there were any good websites on this kind of stuff, cant remember much about cancelation like this. Are there many differnt cases or is it like always cancel 1 item on the bottom cancel 1 item on the top?

factor out quantities of 1. example

(6 + 3)/6 =

(3(3 + 1))/((3)(2))

the 3's cancel or 3/3 = 1 so

(3 + 1)/2 = (6 + 3)/6 and

(h^2 - 10h)/h =

(h(h - 10))/(h(1)) =

h - 10 = - 10 + h

im pretty sure its -10 (because you divide the h away) and just h, becuase you minus powers, unless there is a power inside and outside a bracket.
but yeah, -10+h

you could try webmaths.com
or mymaths.co.uk
or bbc bitesize (gcse)