Law of Sines: Homework please help

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian 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? i need this done

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b

What is the gcf of 20c^3-5c^4+30c^6