A trampoline park that you frequently go to is $9 per visit. You have the option to purchase a monthly membership for $30 and then pay $4 for each visit. Explain whether you will buy the membership, and why. Option A: y = $9x Option B: y = $30 + $4x

1 answer

To determine whether purchasing the monthly membership is a better option than paying per visit, we can set up the equations based on your usage.

Option A: Pay per visit. The cost function is: \[ y = 9x \] where \( y \) is the total cost and \( x \) is the number of visits.

Option B: Monthly membership. The cost function is: \[ y = 30 + 4x \] where \( y \) is the total cost and \( x \) is the number of visits.

Now, we can compare the two cost functions to find the break-even point, which is when both costs are equal:

\[ 9x = 30 + 4x \]

To solve for \( x \):

  1. Subtract \( 4x \) from both sides: \[ 9x - 4x = 30 \] \[ 5x = 30 \]

  2. Divide by 5: \[ x = 6 \]

This means that if you plan to visit the trampoline park more than 6 times in a month, the membership option will be cheaper.

  • If you visit 6 times:

    • Option A: \( 9 \times 6 = 54 \)
    • Option B: \( 30 + 4 \times 6 = 30 + 24 = 54 \) (break-even)
  • If you visit 7 times:

    • Option A: \( 9 \times 7 = 63 \)
    • Option B: \( 30 + 4 \times 7 = 30 + 28 = 58 \) ( membership is cheaper)
  • If you visit 5 times:

    • Option A: \( 9 \times 5 = 45 \)
    • Option B: \( 30 + 4 \times 5 = 30 + 20 = 50 \) (pay per visit is cheaper)

Given this analysis, it would make sense to buy the membership if you plan to visit more than 6 times in a month. If you anticipate using the trampoline park less than or equal to 6 times, then it would be more cost-effective to pay the regular fee of $9 per visit.