Question 772305
Look for ordered pairs in which the coordinates are Years, and Value.
Read these points from the graph if you want.  You can simply fit the values from the graph into slope-intercept form of equation.  The 20000 value should be the y-intercept, and the slope involves the 2500.  You have slope of NEGATIVE 2500.  This is "depreciates 2500 dollars each year".  You would not necessarily need the y value at x=7, depending on what else you want to answer.


You have then, 
m=-2500
b=20000
and slope intercept form for a line is usually used as y=mx+b.
Fill the values and the result is:  y=-2500x+20000