PLZZ help middle school math you just have to explain how to solve it. please don't put big words so I can understand and my teacher will think its me...lol​

(write as unit rate) 12 meters in 28 seconds

What term makes it inconsistent y=2x - 4

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