PLEASE HELP IM SO BAD AT MATH

Given: f(x) = 2x + 5 and g(x) = x2 and h(x) = -2x h(g(f( = x2+ vx+ x + y

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

Polynomials plz quick 1: subtract and simplify (–y^2 – 4y – 8) – (–4y^2 – 6y + 3)