Four times a number, added to 9, is 37

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Asailor is looking at a kite. if he is looking at the kite at an angle of elevation of 36and the distance from the boat to the point where the kite is directly overhead is 40 feet, how high is the kite?

What is the solution to the equation below? 3/x-2+6=square root x-2 +8