At the movies, you order 3 boxes of popcorn and a bottle of water. The cost of the bottle of water is $1.75. Your total cost is $9.25. Write an EQUATION to find the cost of one box of popcorn.
3 boxes of popcorn and a bottle of water are $9.25 A bottle of water is $1.75
$9.25 - $1.75 = $7.5 (the price of 3 boxes of popcorn) We divide $7.5 by 3 to know the price of one box of popcorn $7.5 : 3 = $2.5 One box of popcorn costs $2.5