You can make an equation: 6.75 + x = 10
6.75 is the amount you spend on the book, x is the amount you can spend on the drink, and 10 is the total cost.
Solve for x to find how much you can spend on the drink.
6.75 + x = 10
Subtract 6.75 from both sides to isolate x.
x = 3.25
You can spend $3.25 on the drink.
