Which of the following best describes a square root?

Ineed with number 17 i don’t get it at alll

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?

Which of the following is not a subset of {1,2,3}?