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 is $9.25. Write and solve an equation to find the cost of one box of popcorn.

If popcorn is p and water is w the equation can be written as

3p + w = 9.25

because there was 3 boxes of popcorn and one water (hence the coefficients) and the total is 9.25

then plug in 1.75 for w the price of water:

3p + 1.75 = 9.25

you can move stuff around algebraically now (subtract 1.75 on both sides and divide by three on both aides) to get the cost of one box of popcorn (p).

The answer is 2.50