Find the cosine of each acute angle

If there are 12 moths and some have 31 days and others have 30 days how many have 28 days?

Find the vertex of the function given below y=x^2-6x+1

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian bought 4 bottles of water and 1 cup of coffee for his family for $7.15. how much does each bottle of water cost? how much does each cup of coffee cost? i need this done