Which interval or union of intervals represents the values for which ​f(x)​ is ≤ 0? Select the correct choice below and fill in the answer boxes to complete your choice.

(-∞, -1]∪{5}

Step-by-step explanation:

We know that:

f(x) ≤ 0 is true if the graph of the function is intersecting the x-axis or below the x-axis.

So we can just look at the graph, we can see that in the interval:

(-∞, -1]   (the value x = -1 is included, that is why we use the symbol ] instead of the parenthesis)

the graph is below or intersecting the x-axis

and this also happens at x = 5 or just denoted as {5}

Then the correct notation is:

(-∞, -1]∪{5}

step-by-step explanation:

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.