Given that point A is the midpoint of line segment ED, where E( -1,9) and A(4,5), what is the location of point D?

  D(9, 1)

Step-by-step explanation:

A being the midpoint means its coordinates satisfy ...

  A = (E + D)/2

Solving for D, we find ...

  D = 2A -E

  = 2(4, 5) -(-1, 9) = (2·4 +1, 2·5 -9)

  D = (9, 1)

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.