What is \sqrt{68} in simplest radical form?

Pls i really need help on this :/

Which expression is equivalent to sq-80

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

If y varies directly as x2 and y=6 when x=6, find the constant of variation.