The average value of a certain type of automobile was $14,040 in 1994 and depreciated to $4140 in 1999. Let y be the average value of the automobile in the year x, where x = 0 represents 1994. Write a linear equation that models the value of the automobile in terms of the year x.

a. y = -1980x + 14,040
b. y = -1980x - 5760
c. y = - 1/1980 x - 4140
d. y = -1980x + 4140

Question

The average value of a certain type of automobile was $14,040 in 1994 and depreciated to $4140 in 1999. Let y be the average value of the automobile in the year x, where x = 0 represents 1994. Write a linear equation that models the value of the automobile in terms of the year x.

a. y = -1980x + 14,040	
	 b. y = -1980x - 5760	
	 c. y = - 1/1980 x - 4140	
	 d. y = -1980x + 4140

sriram · Answer

if one of them is correct it has to beA

anonymous · Answer

If x=0 represents the year 1994, then $x=5$ represents the year 1999. So, we have the the two points (0,14,040) and (5,4140) in the x-y plane.

anonymous · Answer

$y=mx+b$ is the linear equation that represents the model, where m is the slope and b is the y-intercept. b is known to be $14,040$. m can be found as $b=\frac{4140-14,040}{5-0}=-1,980$. Hence $y=-1980x+14040$, which is answer a.