6pie = x + 2y how do i solve this equation ?

On ryan's last social studies test there were two types of questions true/false worth 3 points each and multiple choice questions worth 4 points each

Five infinity stones cost $16.80. what is the price per infinity stone ?

Milk and ice cream are mixed together for a recipe. the total volume of the mixture is 1 cup. if the milk contains 2% fat, the cream contains 18% fat ,and the mixture contains 6% fat ,how much cream is in the mixture