Answer:
2
Step-by-step explanation:
The y-intercept is where the curve crosses through the y axis (it intercepts it). In this case the y intercept would be worth three dollars at year 0. As years are time, and time is generally placed along the x axis.
Linear functions are those whose graph is a straight line!
You have five numbers 
Among them there is one negative number
this number is smallest.
Note that

Since 6.25>6, then
and these numbers are less than 3
Note that
then
and these numbers are greater than 3.
Therefore, the correct order from the smallest to the greatest is:

The vertex is the center point of the line or the axis of symmetry
So your answer should be (-2, -5)