Use the image to answer the question.

Ben is trying to decide which of two candles to purchase.

The packaging for the first candle states that the height in inches of the candle as a function of time in hours is represented by Function 1.

Function 1: f(x)=−2.5x+25


The packaging for the second candle shows the height in inches of the candle as a function of time in hours is represented by the graph shown in Function 2.

Function 2:

A line is plotted on a coordinate plane. The x-axis representing hours ranges from negative 1 to 10 in one-unit increments. The y-axis representing height in inches ranges from negative 1 to 10 in one-unit increments.

Which candle will burn for the longest period of time?

(1 point)
Responses

The candles will burn for the same length of time.
The candles will burn for the same length of time.

The second candle will burn for the longest period of time.
The second candle will burn for the longest period of time.

There is not enough information given to determine which candle will burn for the longest period of time.
There is not enough information given to determine which candle will burn for the longest period of time.

The first candle will burn for the longest period of time.

1 answer

To determine which candle burns for the longest period of time, we can analyze the information given in Function 1 and the graph for Function 2.

Function 1: The height of the first candle is modeled by the equation \( f(x) = -2.5x + 25 \), where \( x \) is the time in hours.

To find out when the first candle burns out, we set the height \( f(x) \) to 0 and solve for \( x \):

\[ 0 = -2.5x + 25 \] \[ 2.5x = 25 \] \[ x = \frac{25}{2.5} = 10 \]

Thus, the first candle burns out after 10 hours.

Function 2: We don't have the exact equation for Function 2, but we can analyze the graph to determine when the candle burns out. We can check the point where the height reaches 0 on the graph. If the candle's height remains positive until a certain hour (let’s say, for instance, it lasts for 8 hours before hitting 0), we can conclude from the graph.

Assuming you see from the graph that the second candle burns out earlier than 10 hours (such as 8 hours, as an example), we can conclude:

  • The first candle burns out in 10 hours.
  • The second candle, if it burns out at say 8 hours, will burn for a shorter time.

Therefore, without exact values from the graph in Function 2 but presuming it burns out before 10 hours, we can conclude:

The first candle will burn for the longest period of time.