Groucho, harpo, chico, zeppo, and gummo have won 2 tickets to the opera. they will randomly choose which two of them have to attend. how many different 2-person groups are possible?

Which answer is the solution set to the inequality |x|< 9? a. x< -9 or x> 9 b. x> -9 and x< 9 c. x> -9 or x< 9 d. x< 9 and x< 9

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

Afrequency table of grades has five classes (a, b, c, d, f) with frequencies of 3, 13, 14, 5, and 3 respectively. using percentages, what are the relative frequencies of the five classes?