Avat contains 16 gallons of liquid when a drain pipe opens and the liquid begins to leave the vat at a rate of 2 gallons per hour.

At time 0, there are 16 gallons of water.
That gives you point (0, 16).
This point is a dot on 16 on the y-axis.

After 1 hour, the water went sown 2 gallon.
At hour 1, there are now 14 gallons left.
This gives you point (1, 14).
To plot it, start at the origin, (0, 0), go 1 unit right on the x-axis, and 14 units up om the y-axis, and place a dot there.

Now connect the two dots and extend the line down to the right until you intersect the x-axis. You should intersect the x-axis at 8.

The vat contains 16 gallons of liquidso ur y int (original value) is (0,16)...plot that

and it is decreasing at a rate of 2 gallons per hrthat is ur slope ...-2
ur equation would be : y = -2x + 16

so start at (0,16) and since u have a slope of -2, come down 2 spaces and to the right 1...plot thatthen down 2 and to the right 1plot that...keep doing this and u have ur line...u should reach the x intercept at (8,0)