Bethany, Morgan, and Taylor all go to the local activity center after school. Each girl uses a different form of transportation to travel the six miles from the school to the activity center. Bethany walks, Morgan rides her bike, and Taylor takes the bus. Bethany leaves directly after school, and her distance can be modeled by the equation y=4x

. Morgan leaves half an hour after Bethany, and her distance can be modeled by the equation y=8x−4
. Taylor leaves one hour after Bethany, and her distance can be modeled by the equation y=20x−20
. Use the linear function graph. Which girl arrives at the activity center first?

(1 point)
Responses

Taylor
Taylor

Morgan
Morgan

The girls all arrive at the same time.
The girls all arrive at the same time.

Bethany

1 answer

To find out which girl arrives at the activity center first, let's analyze each girl's distance function and calculate the time at which they arrive at the activity center, located 6 miles from the school.

Bethany's Distance Function

Bethany's distance is modeled by the equation: \[ y = 4x \] where:

  • \( y \) is the distance in miles
  • \( x \) is the time in hours

To find the time at which Bethany reaches the activity center (6 miles): \[ 6 = 4x \] \[ x = \frac{6}{4} = 1.5 \text{ hours} \]

Morgan's Distance Function

Morgan starts her journey 0.5 hours after Bethany, so her equation is: \[ y = 8x - 4 \] To find her arrival time taking into account her delayed start (and the fact she travels for \( x - 0.5 \)): If we let \( x \) be the total time from when Bethany starts:

  • Morgan effectively starts at \( x = 0.5 \).

We need to find the time when Morgan reaches 6 miles: Set the equation for Morgan equal to 6: \[ 6 = 8(x - 0.5) \] \[ 6 = 8x - 4 \] \[ 10 = 8x \] \[ x = \frac{10}{8} = 1.25 \text{ hours} \] Since Morgan starts 0.5 hours later, her total travel time is: \[ 1.25 - 0.5 = 0.75 \text{ hours} \]

Taylor's Distance Function

Taylor starts her journey 1 hour after Bethany, and her distance function is given by: \[ y = 20x - 20 \] To find when Taylor reaches 6 miles (with her delayed start): Set the equation equal to 6: \[ 6 = 20(x - 1) \] \[ 6 = 20x - 20 \] \[ 26 = 20x \] \[ x = \frac{26}{20} = 1.3 \text{ hours} \] Since Taylor starts 1 hour later, her total travel time is: \[ 1.3 - 1 = 0.3 \text{ hours} \]

Summary of Arrival Times

  1. Bethany: Arrives in 1.5 hours.
  2. Morgan: Arrives in 1.25 hours (0.75 hours travel time).
  3. Taylor: Arrives in 1.3 hours (0.3 hours travel time).

Conclusion

Morgan arrives first, followed by Taylor, and Bethany arrives last. Therefore, the answer is:

Morgan.