How would I subtract this?

[(8)/(x+h+8)] - [(8)/(x+8)]

2 answers

just like in numerical fractions, form a common denominator, which is this case is
(x+h+8)(x+8)

Also your use of square brackets suggest that you have a typo and you forgot the /h at the end,
which is the usual form of this fraction

I will insert it for you

[(8)/(x+h+8)] - [(8)/(x+8)]/h
= [ (8(x+8) - 8(x+h+8) )/((x+h+8)(x+8))]/h
= [(8x+64 - 8x - 8h - 64)/((x+h+8)(x+8) ]/h
= -8h/(h(x+h+8)(x+8))
= -8/((x+h+8)(x+8))

Usually at this point you would take the Limit of that expression as h ---> 0
and you would get

-8/(x+8)^2
I'm sorry I had to pester you with a problem like that, but my algebra is extremely weak. I understand it now though. Thank you very much! :)