Simplify for me please

What is the value of x in the equation (2)3) (x+6)= -18 a. -36 b. -33 c. -24 d. -18

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

Which two undefined geometric terms always describe figures with no beginning or end?