A company charges $15 per hour plus a $20 setup fee to rent a bouncy house for 3 hours or less. They charge $12 per hour and no setup fee if the bouncy house is rented for more than 3 hours. Sketch a graph of the piecewise function that models this scenario. Use the graph to select the correct equation for the function where x

is the number of hours and y
is the total cost.(1 point)
Responses

y={15x+20, 0<x≤312x, x>3
y equals left brace line 1 15 times x plus 20 comma 0 less than x less than or equal to three line 2 12 times x comma x greater than 3

y={15+20, 0<x≤312, x>3
y equals left brace line 1 15 plus 20 comma 0 less than x less than or equal to three line 2 12 comma x greater than 3

y={15+20x, 0<x≤312, x>3
y equals left brace line 1 15 plus 20 times x comma 0 less than x less than or equal to three line 2 12 comma x greater than 3

y={15x+20, 0<x<312x, x≥3

1 answer

To model the cost of renting a bouncy house as a piecewise function, we can outline the two scenarios based on the number of hours rented:

  1. For rentals of 3 hours or less (i.e., \( 0 < x \leq 3 \)):

    • The cost is \( y = 15x + 20 \) (where \( x \) is the number of hours).
  2. For rentals of more than 3 hours (i.e., \( x > 3 \)):

    • The cost is \( y = 12x \).

Thus, we can represent this as a piecewise function:

\[ y = \begin{cases} 15x + 20 & \text{for } 0 < x \leq 3 \ 12x & \text{for } x > 3 \end{cases} \]

Now, let's match this with the options given in your responses:

  1. \( y = { 15x + 20, 0 < x \leq 3; 12x, x > 3 } \)
  2. \( y = { 15 + 20, 0 < x \leq 3; 12, x > 3 } \)
  3. \( y = { 15 + 20x, 0 < x \leq 3; 12, x > 3 } \)
  4. \( y = { 15x + 20, 0 < x < 3; 12x, x \geq 3 } \)

The correct response is clearly the first one:

\[ y = { 15x + 20, 0 < x \leq 3; 12x, x > 3 } \]