Francis teaches the piano. he charges each student an enrollment fee of $100 plus $15 per hour of piano lessons. the average cost of lessons for a student per hour is $25.

if h represents the number of hours a student spends in lessons, which equation can be used to find the value of h?

The temperature of a chemical solution is originally 21 ? c . a chemist heats the solution at a constant rate, and the temperature of the solution 75 ? c after 1212 12 minutes of heating. the temperature, tt t , of the solution in ? c is a function of x , the heating time in minutes. write the function's formula.