You can put this solution on YOUR website! y=Mx+B WHERE M=SLOPE & B= THE y INTERCEPT.
(4,-7) (8,-1)
m=(Y2-Y1)/X2-X1)
m=(-1+7)/(8-4)=6/4=1.5 ans. for the slope.
-7=1.5*4+b
-7=6+b
b=-7-6
b=-13 ans. for the Y intercept.
Y=1.5X-13 (graph 300x200 pixels, x from -6 to 10, y from -15 to 10, 1.5x -13).