Find 3 poins in the form of (x, y) to plot
Give y any value and find x ( you could give x any value and find y, yet is easier this way for me)
If y=0
X-4•0=18; x=18 so 1 point is (18,0)
If y=-1
X-4(-1)=18; x= 18-4=14 so 2nd point is (14, -1)
If y= 1
X-4•1=18; x=18+4=22 so 3rd point is (22,1)
