A pizza place charges a $5 delivery fee, and $12.50 for each pizza.
This situation can be modelled by the following equation
[tex]y=12.5x+5[/tex]
Where x represents pizzas, and y represents a cost.
(1) The image below shows the graph
(2) As you can observe in the graph above, there's no proportional relationship because the equation doesn't have the form y=kx.
At a different place, there is a $4 delivery fee, and each sandwich costs $14.
The equation of this situation is
[tex]y=14x+4[/tex]
(3) The graph below shows both situations
If we compare the lines, we observe that they intercept at (0.667, 13.333), which means they have the same cost there. Additionally, the lines are both increasing, and they are not proportional.
On the other hand, they represent close costs and fees but not the same ones, they are different situations.
