Find the solution of the system of equations 2x-4y=32 2x-8y=48

Simplify 15(x - 4)(x -1)-3(x + 4)(x - 1) with steps

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?