Solve for x 8x^2-7x-18=0

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 is the slope of the line shown below?

Edger needs 6 cookies and 2 brownies for every 4 plates how many cookies and brownies does he need for 10 plates