How many terms are in the following expression?
-4a +8C -4b +3

Which of the following contains a variable?

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

For f(x) = 3x+1 and g(x) = x2 - 6, find (g/f)(x)