Please help me with this problem:)

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

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

Acolony contains 1500 bacteria. the population increases at a rate of 115% each hour. if x represents the number of hours elapsed, which function represents the scenario? f(x) = 1500(1.15)" f(x) = 1500(115) f(x) = 1500(2.15) f(x) = 1500(215)