Which of the following expressions represents the difference of eight and n

Given f(x) = 17-x^2what is the average rate of change in f(x) over the interval [1, 5]?

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?

Aman is 6 feet 3 inches tall. the top of his shadow touches a fire hydrant that is 13 feet 6 inches away. what is the angle of elevation from the base of the fire hydrant to the top of the man's head?