The local zoo is filling two water tanks for the elephant exhibit. one water tank contains 34 gal of water and is filled at a constant rate of 4 gal/h. the second water tank contains 30 gal of water and is filled at a constant rate of 2 gal/h. explain. let x = the number of hours the tanks are filling and let y = the number of gallons in the tank. what are the constraints on the system?

a. both x0, y0
b. x0 only
c. y0 only
d. there are no constraints on the system.