A grocery sells shampoos, soaps, and toothpastes. Two shampoos, one soap, and one toothpaste cost $20; one shampoo, two soaps, and three toothpastes cost $28; three shampoos, one soap, and two toothpastes with a $4 loyalty credit cost $24. Find the price of one shampoo, one soap, and one toothpaste.
[6]