8/3+(-94)=? i am unsure of how to find this. i misse a day in mathmatics and cannot find the answer.

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

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

Carmen ayer en el mercado compro 3/4 kg de guayabas, 6/8 kg de peras, 1/2 kg de naranjas ¿cuantos kilogramos de fruta compro?