How to square the standard deviation? how do you get the bottom number so you can actually square it? for instance, 22/6 squared is 1.91, where did they get the 6 from?

Evaluate the given expression if m=45 |-3m|

Astandard deck of cards contains 52 cards. one card is selected from the deck. (a) compute the probability of randomly selecting a seven or king. (b) compute the probability of randomly selecting a seven or king or jack. (c) compute the probability of randomly selecting a queen or spade.

Simply 8x squared + 5(7x squared- x) - 2x =