the easy way is to input x values and get y values to plot
remembmer
x tells how far to teh right from center it the point is
y tells how far up from the center the point is
example
if x=0
y=3(0)-4
y=-4
go -4 up on the x axis (or 4units down) and plot a point
now
if x=1
y=3(1)-4
y=3-4
y=-1
go 1 unit right and 1 unit down and plot a point
now you have 2 points
draw a straight line through them
