PLEASE HELP:( I CANT FAIL what is the average rate of change for this quadratic function for the interval from x=2 to x=4?

A)6
B)-12
C)-6
D)12

Can someone me with the property questions for 12 13 and 14 plz

Solve the equation by completing the square. x^2+2x=17

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters