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}

there will be 35 boys in each team. : )