Greg has collected 4,385 pennies and hannah has collected 3,899 pennies. how many times as great as the value of 3 in 4,385 is the value of 3 in 3,999?

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

What kinds of numbers make up the set of numbers called the real numbers? give examples when you explain a number type. there are a limited set of types of numbers, but an unlimited number of examples of these numbers.

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.