What is the completely factored form of this polynomial? 81x4 − 16y4 A. (3x2 + 2y2)(9x + 4y)(9x − 4y) B. (9x2 + 4y2)(9x2 − 4y2) C. (9x2 + 4y2)(3x − 2y)2 D. (9x2 + 4y2)(3x + 2y)(3x − 2y)

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.