Chứng minh : giao điểm của hình chữ nhật là tâm đối xứng của hình chữ nhật đó

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.

this may not be at all, but i use the same website you're using for school, and if i'm stuck doing one of these i try to look for it on the section.

zero

step-by-step explanation:

f(2)= x-2

plug in the 2 in the "x"

f(2)=2-2

f(2)=0