first, let's break the equation down.
y=7x-4
-4 represents your staring coordinate, or your y-intercept. This is because -4 does not have an x after so you know it is equal to your y value. So you start at (0,-4)
Now all you need to do is the y=7x part.
The 7x represents your slope.
Slope is equal to rise/run or y/x.
So for each coordinate, you go up 7 and to the right 1.
(0,-4)
(1,3)
(2,10)
I hope this helps!