Answer:
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Step-by-step explanation:
The order in which the teachers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
1 from a set of 2(Either Mrs. Vera or Mr. Jan).
3 from a set of 18 - 2 = 16. So

1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
It can be defined as a positive..
it is also a inverse function to the natural exponential function
i hope that helps
<u>Given:</u>
The given function is 
We need to determine the reflection of f(x) over the x - axis
<u>Reflection over x - axis:</u>
The translation rule to reflect over the x - axis is given by

Reflecting the function over the x - axis, we get;

Multiplying -1 to both sides of the equation, we have;

This can be written as

Hence, the reflection of the function over the x - axis is 
Thus, Option A is the correct answer.