The formula is y=0.5m+20
You start (0,20) then for each mile you increase by 0.5.
Or
Since the x axis is by two, then every two miles you increase by 1 mile. So (0,20); (2,21); (4,22); (6,23); (8,24).
You start (0,20) then for each mile you increase by 0.5.
Or
Since the x axis is by two, then every two miles you increase by 1 mile. So (0,20); (2,21); (4,22); (6,23); (8,24).