Hurry! what is the solution to this equation? 3(a−4)+1=9−a a = 3 a = 5 a = 6 a = 10

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?