Bella bought b boxes of cookies to bring to a party. Each box contains 18 cookies. She decides to keep two boxes. She brings 90 cookies to the party. How many boxes of cookies did Bella buy? Using b for boxes, determine the correct equation and the unknown number in this situation. (1 point) Responses 18b−2=90; b=5 18b−2=90; b=5 2b−18=90; b=54 2b−18=90; b=54 18b−36=90; b=7 18b−36=90; b=7 18b−36=90; b=6

Answer 1

To find how many boxes of cookies Bella bought, let's break down the problem step by step.

1. Determine the total number of cookies Bella has:

   • Bella bought \( b \) boxes of cookies.
   • Each box contains 18 cookies.
   • Therefore, the total number of cookies Bella has is \( 18b \).

2. Calculate the number of cookies she brings to the party:

   • Bella keeps 2 boxes of cookies for herself.
   • The number of cookies in those 2 boxes is \( 2 \times 18 = 36 \) cookies.
   • Therefore, the number of cookies she brings to the party is the total cookies minus the cookies she keeps: \[ 18b - 36 \]

3. Set up the equation:

   • We know that Bella brings 90 cookies to the party. We can equate that to the expression we have for the cookies she brings: \[ 18b - 36 = 90 \]

4. Now, let's solve for \( b \): \[ 18b - 36 = 90 \] \[ 18b = 90 + 36 \] \[ 18b = 126 \] \[ b = \frac{126}{18} \] \[ b = 7 \]

So the correct equation is \( 18b - 36 = 90 \), and the unknown number of boxes \( b \) is 7.

The final answer is: \[ 18b - 36 = 90; \quad b = 7 \]