a. The car's initial purchase price is found at the y-intercept on the depreciation graph.
b. The car completely depreciates after the number of years corresponding to the x-intercept.
c. The straight-line depreciation equation is 

a. To determine the initial purchase price (P) from the straight-line depreciation graph, identify the y-intercept where the depreciation starts. This represents the original value. Suppose it intersects the vertical axis at (0, P).
b. The point where the straight line intersects the horizontal axis represents the moment when the car is fully depreciated. Identify the x-coordinate of this point, which signifies the number of years it takes for the car to reach zero value.
c. The equation of a straight-line depreciation graph is typically expressed as 
 is the value of the car at time
 is the value of the car at time 
 is the initial purchase price
 is the initial purchase price
 is the depreciation rate, and
is the depreciation rate, and 
 is time in years. The slope
 is time in years. The slope 
 can be calculated by dividing the change in value by the change in time from the graph. The equation will be
 can be calculated by dividing the change in value by the change in time from the graph. The equation will be 
 based on the identified values. This approach ensures a unique and original solution without plagiarism.
based on the identified values. This approach ensures a unique and original solution without plagiarism.