The numerical factor of a multiplication expression that contains a variable is called a what ?

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

What is the definition of exponential decay?

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?