Start at the point given. Count up and across until you touch the graph again.
Go up 2 and right 1 = 2/1 which is a slope of 2x
now the next part we need is the y-intercept.
We can see it because its off screen but at the rate its going up (slope) we can determine its 4 (because for every 2 vertical moves it moves 1 right).
for its y=2x+4
