A baker delivers cookies to offices

The bakery charges a $5 delivery fee

The bakery charges a total of $20.00 for delivering 12 cookies.

The bakery charges a total of $27.50 for delivering 18 cookies

Which equation represents the total charge in dollars , y, for delivery of x cookies?

answers:

y = 1.25x + 5

y = 5x + 1.25

y = 1.25x + 6

y = 5x + 7.50

1 answer

To find the equation that represents the total charge \( y \) for the delivery of \( x \) cookies, we can start by analyzing the given information.

Given Data:

  1. For 12 cookies, the total charge is $20.00.
  2. For 18 cookies, the total charge is $27.50.
  3. There is a $5 delivery fee.

Setting Up the Equations:

Let \( c \) be the cost per cookie.

The total charge can be expressed as: \[ y = cx + 5 \]

From the first data point:

  • For 12 cookies: \[ 20 = 12c + 5 \] Subtracting 5 from both sides: \[ 15 = 12c \] Dividing by 12: \[ c = 1.25 \]

From the second data point:

  • For 18 cookies: \[ 27.50 = 18c + 5 \] Subtracting 5 from both sides: \[ 22.50 = 18c \] Dividing by 18: \[ c = 1.25 \]

Conclusion:

We have confirmed that the cost per cookie \( c \) is indeed $1.25.

Final Equation:

Now, substituting the value of \( c \) back into the total charge equation: \[ y = 1.25x + 5 \]

Thus, the equation that represents the total charge in dollars \( y \) for the delivery of \( x \) cookies is: \[ \boxed{y = 1.25x + 5} \]