Algebra
posted by sherry .
Pepperidge Farm Goldfish is a snackfood for which 40% of its calories come from fat. Rold Gold Pretzels receive 9% of their calories from fat.How many grams of each would be needed to make 620g of a snack mix for which 15% of the calories come from fat?

let the amount of goldfish needed by x g
then the amount of pretzels needed is 620x g
.4x + .09(620x) = .15(620)
times 100
40x + 9(620x) = 15(620)
40x  5580  9x = 9300
31x = 14880
x = 480
Needed: 480 g of goldfish, and 140 g of pretzels