Solve the equation. type the integer with it 7x=21

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.

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Does the point (1, sqrt 7) lie on circle shown.