Someone please help?! Which of the following is a complex number?

-4+ square root 7/3

4/ square root 3 - 7 square root 3/5

5/2 - square root 15

2/3 + square root - 27/28

The solution set for 5v2 – 125 = 0 is

Three times the sum of a number and seven is negative thirty-six. what is the number?

Abag contains 3 red marbles, 2 blue marbles, and 2 green marbles. one marble is picked, then another marble. assume that the selections are made with replacement. a) find the probability of picking two red marbles with replacement. b) find the probability of picking a red marble and a blue marble. assume the selections are made without replacement. c) find the probability of picking two red marbles without replacement. d) find the probability of picking a red marble and a blue marble without replacement.