One side of a triangle is 7 feet longer than the second side. The third side is 2 feet longer than the second side. The perimeter of a triangle is 42 feet. Find the length of each side.

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?