Ok, so you need to use the equation y2-y1/x2-x1 to find the slope. So (18.5-4.25)/(2-0.5) so 14.25/1.5 , calculate that and you get 9.5 which is your slope, apply that to the slope formula which is y=mx+b where (m) is slope and (b) is y intercept and you get y=9.5x-0.5
