You can put this solution on YOUR website! y=3x-1
The slope is 3 (3x)
The y intercept is -1
Therefore, you plot your first point at (0,-1) then since the slope is 3, you go to the right one point and up three, that is where the second point is plotted.
y=4x
The slope is 4 (4x)
The y intercept is 0
Therefore, you plot your first point at (0,0) then since the slope is 4, you go to the right one point and up four, that is where the second point is plotted.