How do you know what number fits in the equations? like this one: y=7/2x-2
i tried to put those numbers on the picture but still dont get the right answer. i haver the answer key. so i know the answer but i want to be able to get the right answewr by myself could somebody ?

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.

Ametal rod needs to be 9 feet and 5.5 inches in length. the sections of the poles being used are each 1 foot and 10.5 inches long. how many 1ft 10.5in sections would be needed to complete the 9ft 5.5in metal rod? and how many inches of material will be left?

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!