F(x)=4²+1 and g(x)=x²-5 find (f-g)(x)

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

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

Find an bif a = {3, 6, 9, 12) and b = {2, 4, 6, 8, 10).