<span>483 / 322 = 1.5. $1.5 is the cost for one button. Hope this helps. :)</span>
For this you count rise over run aka how many up divided by how many over starting from 0. here it’s 7 up and 3.5 side, 7 divided by 3.5 is 2 and the line is going down so it’s negative 2 (D)
(0,-9) could be a solution