Don't take my word but looking at this, you could only assume the second set of coordinates are 0,2 right? If the intersection of y is at 2. So using y = mx +c start to sub in values. Y = mx + 2. Now use both coordinates to find the gradient which is given as the change in y divided by the change in x... So 6-2/12 so 4 divided by 12. And then plug that into the MX part so it would be y = 4/12x + 2
Hopefully someone will give you the full right answer this is just an assumption