Answer:

y = -1250x + 16250

x = ownership of automobile in years    

y = value of automobile

This answer is found by looking at the slope using two points from the graph.  

It appears from Year One the automobile value is $15000 and in Year 5 the value is $10000.

Use the slope formula to solve the problem:

This makes the equation y = -$1,250x + b.  If the graph is moved to Year 0 it would change by $1,250 making the y-intercept or original cost $16,250. 

This results in the equation, y = -$1,250x + $16,250.