'Kay, doing college algebra, I've done most of these myself but I'm stuck on these. My teacher sadly doesn't have help time whenever I'm out of class. If I could get an explanation, that would be great. The book doesn't help, it just gets very technical with math terminology when I'm already very bad at it, lol.

4.Using the function, f(x)=8-x, find the following.

a)f(x+h)

b)f(x+h)-f(x)

c)f(x+h)-f(x)

------------

h

I know, for example f(x+h)-f(x) using f(x)=5-x was -h, but I don't understand how its simplifies to just one letter. =/

10.Find (f o g)(x) and (g o f)(x) [That o is that really small circle symbol I don't have a key for.]

f(x)=10x-1, g(x)=8-4x.

11.For the given functions, find (f o g)(x) and (g o f)(x) and the domain of each.

f(x)=3x+1, g(x)=square root of x