Which ratios are equivalent to the ratios in the table? Check all that apply. 20:4 4:22 20:5 7:35 40:8

Ineed to learn how to solve this problem

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.

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.