Question 60235
f(x) = 1/(x+10)
g(x) = x + 5
f(g(x)) = f(x + 5)
        = 1/{(x+5)+10} [Replacing x by x+5 in f(x)]
        = 1/(x+15)
==> f o g (x) = 1/(x+15)

Domain of f o g = {x : x is real and not equal to -15}

Good Luck!!!