we can calculate the slope with 2 points one more to the right than the other
i will use this points

and the equation of the slope

where the point (x2,y2) is the point to the right on this case (4,140) and (x1,y1)=(2,70)

the slope is 35, so you multiply the hours by 35 to find the Miles
Miles at 10 hours
we just multiply the hours by 35
