Mary takes 9 grapes from Robin and gives 4 back. Write a subtraction problem to describe how many grapes Robin has

Find the balance at the end of 4 years if 1000 is deposited at the rate of

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

Colby and jaquan are growing bacteria in an experiment in a laboratory. colby starts with 50 bacteria in his culture and the number of bacteria doubles every 2 hours. jaquan starts with 80 of a different type of bacteria that doubles every 3 hours. let x equal number of days. colbys experiment follows the model: a.) y=50*2^x b.) y=50*2^8x c.) y=50*2^12x jaquans experiment follows the model: a.)80*2^x b.)80*2^8x c.)80*2^12x