The x column gives you the x intercepts. While the y column gives you the y intercepts.
What you have to do is subtract 3 2/15 from 7 5/9. You can also use decimals but that doesn't work all the time since the are infinite numbers (you will see what I mean later on) So what you can do is find the improper fraction of each one, and subtract it from each other. It would be 68/9 - 47/15, which would give you a total of 4 19/45. YOU'RE WELCOME :)
Volume of a pyramid= 1/2 * base area * height
