According to research on calorie consumption, 2 hours of swimming burns 600 calories. Choose the proportion that will give H, the number of hours of swimming needed to burn 1000 calories.

Bring the fraction a/a-4 to a denominator of 16-a^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

Arectangle has a width of 5 cm and a length of 10 cm. if the width is increased by 3, how does the perimeter change?