For tax​ purposes, a business depreciates its ​$240 comma 000 building using​ "straight-line depreciation" over 12 years by reducing its value by ​1/12 of its original value each year. If we assume that the value of the building can be found or estimated at any point of time during this​ period, the value of the building can be modeled by the function yequals240 comma 000minus20 comma 000​x, where x is the number of years. Complete parts ​(a) through ​(c).

What is the meaning of the​ x-intercept? Select the correct choice below and fill in the answer​ box(es) to complete your choice.
​(Type integers or​ decimals.)
A.
The value of the building decreases by ​$
  
enter your response here per year.
B.
At the beginning of the
  
enter your response here ​years, the building is worth ​$
  
enter your response here.
C.
The value of the building is ​$
  
enter your response here at the end of the
  
enter your response here years.
D.
The value of the building increases by ​$
  
enter your response here per year.

1 answer

To analyze the given function for straight-line depreciation of the building, we can start by examining the function itself:

\[ y = 240,000 - 20,000x \]

In this equation:

  • \(y\) represents the value of the building after \(x\) years.
  • The term \(-20,000x\) indicates that the building depreciates by $20,000 each year.

Finding the x-intercept

The x-intercept occurs when \(y = 0\). To find the x-intercept, we set the equation to zero and solve for \(x\):

\[ 0 = 240,000 - 20,000x \]

Rearranging gives:

\[ 20,000x = 240,000 \]

Now, solving for \(x\):

\[ x = \frac{240,000}{20,000} = 12 \]

Meaning of the x-intercept

The x-intercept of the function occurs at \(x = 12\) years, which means the value of the building reaches $0 at the end of 12 years.

Selecting the Correct Choice

Now let's interpret the meaning of the x-intercept:

C. "The value of the building is $0 at the end of the 12 years."

Filling in the answer boxes:

C. The value of the building is $0 at the end of the 12 years.

Summary:

  • The x-intercept is 12 years.
  • This represents the point in time when the building's value has completely depreciated to $0.