Find the sum and choose the correct answer.
2n 3 + 4n 2 - 7 and -n 3 - 8n - 2
-n3 + 4n2 - 8n - 9
n3 + 4n2 - 8n - 9
n3 + 4n2 - 8n - 5
n3 - 4n2 -9

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