If f(x)=2^x and g(x)=2^x+4 -5 explain how the graph g(x) has been transformed from the graph of f(x) ?

Becca wants to mix fruit juice and soda to make a punch. she can buy fruit juice for $3 a gallon and soda for $4 a gallon. if she wants to make 28 gallons of punch at a cost of $3.25 a gallon, how many gallons of fruit juice and how many gallons of soda should she buy?