What is the rule for changing a negative exponent into a positive?

Jackie purchased 3 bottles of water and 2 cups of coffee for the family for $7.35. ryan bought 4 bottles of water and 1 cup of coffee for his family for 7.15. how much does each bottle of water cost? how much does each cup of coffee cost?

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

Lv beethoven software supplies customized software to a managed healthcare system. lv beethoven software's costs for the software is $1,723,000. lv beethoven software sells the software to the healthcare system for $3,816,981.10. overhead expenses are estimated at 47% of the selling price. what is lv beethoven software's net profit to the nearest dollar?