step 1.Above you see the Table,
that contains 3 points from the graph.
Let's call the axes: a and b.
step 2. The starting value is 5, because at that height the
graph starts at the vertical axis.
step 3. Now the amount the graph goes down per step of 1 for x:
If you go 3 steps to the right, then you go down 2 steps. So:
If you go 1 step to the right, then you go down of a step.
step 4. The Formula becomes: b = 5 - x a