Find the missing number in the following sequence 21,3,42,_84,12

Angles r and s are complementary. the measure of angle r is 31 degrees. which equation can be used to find angle s?

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.

Hurry which expression is equivalent to 3√x^5y?