Acake recipe requires 3 1/4 cups of flour for 13 servings and 4 1/2 cups of flour for 18 servings. how much flour is required to make a cake that serves 28?

Ronnie is making short and long necklaces with only one chain and one pendant per necklace. write an expression that shows how much it will cost ronnie to make s short necklaces and n long necklaces. then find the cost for 3 short necklaces and 2 long necklaces me