When their are angles at a certain level like 90 degrees, what's another name for these angles?

Simplify a7/a4 a) 1/a3 b)-a/a2 c)a4/a3 d)a3

The tuition costs, c, for a local community college are modeled by c(h) = 250 + 200h, where h represents the number of credit hours taken. the local state university has tuition costs, s, modeled by the function s(h) = 300 + 180h. how many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)