A mooncake with two egg yolks costs $2 more than a mooncake with one egg yolk. The cost of 6 mooncakes with two egg yolks and 5 mooncakes with one egg yolk is $130.80. Find the cost of a mooncake with two two egg yolks.
6(x + 2) + 5(x) = $130.80 6x + 12 + 5x = 130.80 11x = 118.80 x = 10.80, the cost of a moon cake with one egg yolk. Add 2 for the cost of the two egg yolk cake, and your answer is $12.80
