Question

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.

Answer 1

You first have to set up the two equations. Y is equal to the total number of gallons in a tank and x is equal to the number of hours the tanks are filling.

Since the two equations both equal y I can make them equal each other. I then solved for x as you see and got -4.

Once I found my x value I now needed to find my y. You only needed to chose one equation to solve for y, so I decided to do the first one. I plugged in -4 where my x value currently was and solved for y. I got 2.


If you have any questions please comment!! Hope this helps!!