Please help! I’ll also give brainliest! Thank you!

If f(x)=x^3 and g(x)=2x+7 when g(x)=-5

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

Given the median qr and trapezoid mnpo what is the value of x?