Please please help help this is for the brainies y’all are amazing thank you

What is the missing constant term in the perfect square that starts with x^2 -20x

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.

Which inequality is equivalent to -3x < -12? x < 4 , x < -4 , x > 4, x > -4