Answer:
A) y = 24000 - 3000 x
B) 4 years
Explanation:
Part A
We need to write a formula for the car value y, after x years, knowing that:
- The initial car values is $24,000
- The car value depreciates (decreases) $3,000 per year
So to calculate the car value after x years we must subtract to the initial car value (fixed independent term) how much the value has depreciated, that is $3000 multiplied by the amount of years x.
So the car value will be calculated as:
y = 24000 - 3000 x
Part B
The question asks after how many years the car value will be $12000
So, y = 12000
we need to calculate the years x
Lets replace in the formula and solve for x:
12000 = 24000 - 3000 x
we must isolate x by doing the opposite operations:
12000 - 24000 = 24000 -24000 -3000 x
-12000 = -3000 x
-12000 / (-3000) = -3000 x / (-3000)
4 = x
After 4 years the car value will be $12000