The store charges $2.50 for a bottle of soda and $1.25 for a bottle of water. Write an equation in standard form for the number of soda (s) and water (w) bottles that you can buy with $15. PLZ HEL

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of