What single decimal multiplier would you use to decrease by 13% followed by a 6% decrease?

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

What does x = in this equation x+3+2x=x+5

0if x and y vary inversely and y=6 as x=7, what is the constant of variation?