Terrence buys a new car for [tex]$\$[/tex]20,000[tex]$. The value of the car depreciates by $[/tex]15\%[tex]$ each year. If $[/tex]f(x)[tex]$ represents the value of the car after $[/tex]x[tex]$ years, which function represents the car's value?

A. $[/tex]f(x) = 20,000(0.85)^x[tex]$
B. $[/tex]f(x) = 20,000(0.15)^x[tex]$
C. $[/tex]f(x) = 20,000(1.15)^x[tex]$
D. $[/tex]f(x) = 20,000(1.85)^x$



Answer :

Sure, let’s break down the process to find the function that represents the car’s value after [tex]\( x \)[/tex] years, given that the car’s value depreciates by 15% each year.

1. Initial Condition: Terrence buys a car for [tex]$20,000. 2. Depreciation Rate: Each year, the value of the car decreases by 15%. 3. Depreciation Factor: To understand how depreciation works mathematically, if the car depreciates by 15%, it retains 85% (100% - 15% = 85% or 0.85) of its value each year. 4. General Formula: The value of the car after one year would be \( \$[/tex]20,000 \times 0.85 \). If you want to find the value after two years, it would be [tex]\( \$20,000 \times 0.85 \times 0.85 \)[/tex] or [tex]\( \$20,000 \times (0.85)^2 \)[/tex]. This pattern continues:

After [tex]\( x \)[/tex] years, the value of the car would be [tex]\( \$20,000 \times (0.85)^x \)[/tex].

5. Conclusion: Hence, the function [tex]\( f(x) \)[/tex] that represents the car’s value after [tex]\( x \)[/tex] years is:
[tex]\[ f(x) = 20,000 \times (0.85)^x \][/tex]

So, the correct function is:
[tex]\[ f(x) = 20,000(0.85)^x \][/tex]

Thus, the best choice among the given options is:
[tex]\[ \boxed{f(x) = 20,000(0.85)^x} \][/tex]