Formula of minimmum pressure

In a school 2/3 of the students study a language of those who study a language 2/5 study french

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.

Which equation represents h for right triangle abc