Michelle is making goodie bags for Christmas filled with chocolates and candy. Chocolates cost $3.00 per lb. Candy cost $2.00 per lb. Michelle bought a total of 15 pounds of candy and chocolate and spent $40. How many pounds did she buy of each?
She bought x pounds of chocolates at $3 a pound, so those x pounds of chocolates cost her $3x dollars.
She bought 15-x pounds of chocolates at $2 a pound, so those 15-x pounds of chocolates cost her $2(15-x) dollars.
3x + 2(15 - x) = 40
3x + 30 - 2x = 40
x + 30 = 40
x = 10
Edwin