The answer is C. All students enrolled at Springfield high school.
I’m sorry i don’t know the answer but i need to ask another question but i gave up answer a question first sorry
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.
Start with -3x + 2 = -7
Subtract 2 from each side
-3x = -9
Divide each side by -3
x = 3