What is the equation to represent the sequence 5,10,20

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

Evaluate-27 ^4/3/8 a) - 81/16 b) 81/16 c) 16/81

Compare the following pair of numbers a and b in three ways. a. find the ratio of a to b. b. find the ratio of b to a. c. complete the sentence: a is percent of b. a=120 and b=340 a. the ratio of a to b is . b. the ratio of b to a is . c. a is nothing percent of b.