I need help with this math problem?

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

The sum of the squares of two numbers is 8 . the product of the two numbers is 4. find the numbers.

If abcde is reflected over the x-axis and then translated 3 units left, what are the new coordinates d? are he re