The relationship between V, the value of his car, in dollars, and t, the elapsed time, in years, since he
purchased the car is modeled by the following equation,
V = 22,500 - 10"
How many years after purchase will Vishal's car be worth $10,000?
Give an exact answer expressed as a base-10 logarithm.
years

Respuesta :

Answer:

t = -24*log(2/3)

Step-by-step explanation:

The expression is:

V = 22,500*10^(-t/12)

Replacing with V = 10,000 and isolating t, we get:

10,000 = 22,500*10^(-t/12)

10,000/22,500 = 10^(-t/12)

4/9 = 10^(-t/12)

(2/3)² = 10^(-t/12)

2*log(2/3) = -t/12

-12*2*log(2/3) = t

t = -24*log(2/3)

Answer:

The number of years after purchase at which Vishal's car will be worth $10,000 is [tex]Log_{10}\left (\frac{9}{4} \right )^{12}[/tex]  years

Step-by-step explanation:

The relationship is given as follows

Value, V of the car = 22500×[tex]10^{-t/12}[/tex]

Therefore, when the car is $10,000 we will have

$10,000 = 22,500×[tex]10^{-t/12}[/tex]

Which will give;

[tex]\frac{10000}{22500} =\frac{4}{9} = 10^{-\frac{t}{12}}[/tex]

Hence;

[tex]Log\frac{4}{9} = Log(10^{-\frac{t}{12}} )[/tex]

Therefore;

[tex]-\frac{t}{12}\times Log_{10} 10 = Log\frac{4}{9}[/tex]

[tex]\because Log_{10} 10 = 1, \ we \ have; \ -\frac{t}{12} = Log_{10}\frac{4}{9}[/tex]

Which gives;

[tex]t = -12 \times Log_{10}\frac{4}{9} \ or \ t = Log_{10}\left (\frac{4}{9} \right )^{-12}[/tex]

[tex]\therefore t = Log_{10}\left (\frac{9}{4} \right )^{12}[/tex] years

Evaluated, the above equation becomes t = 4.226 years

Therefore, the number of years after purchase at which Vishal's car will be worth $10,000 = [tex]Log_{10}\left (\frac{9}{4} \right )^{12}[/tex]  years.