How to you simplify to the lowest term with fractions

Someone . me. compound probability

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

Astudent drew a circle and two secant segment. he concluded that if pq ~= ps, then qr ~= st. do you agree with the student’s conclusion? why or why not?