The parabola y=z^2 is scaled vertically by a factor of 5/2 what is the equation of the new parabola

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

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)