The local zoo is filling two water tanks for the elephant exhibit. one water tank contains 30 gal of water and is filled at a constant rate of 7 gal/h. the second water tank contains 18 gal of water and is filled at a constant rate of 4 gal/h. let x = the number of hours the tanks are filling and let y = the number of gallons in the tank. write and solve a system of equation to determine when the two tanks will have the same amount of water. explain

this question was at my math test. can someone explain to me how to do this kind of question step by step?

fyi, the answer is they will never have the same amount of water because the solution to the system is (–4,2). it is not possible to have time be –4 hours.