The model shows the expression 21 + 9. Which expression is equivalent to this sum?
O 3(7+3)
O 3(7) + 3
O 3+7+3
07(3+3)

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.

The two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16

8. kelly wants to buy a magazine that is $25. later the magazine was marked up an additional 20%. what is the new price?