Please somone tell me the right answer

Factor completely. 4p^2 + 36p + 81 express the answer in the form (ap + b)^2

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

Write an equation of the line that passes through 9,2 and is parallel to the line y=5/3x+9