Which of the following equations has exactly one solution? A. 2(6x + 7) = 12x +14
B. 4x + 5 = 5x - 6
C. 3x-12=3 (x-4)
D. 5x - 6 + 2x = 7x - 6

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?