Is this correctly done?

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

You’re repairing a large rectangular aquarium. the final step is to cover the glass with a protective film. the front and back of the aquarium measure 4 meters by 2 meters, and the sides of the aquarium measure 3 meters by 2 meters. how many square meters of protective film do you need? ( )

What are the coordinates of the midpoint of ab? ,1/2) /2,-1) ,-3/2) /2,-2)