And what’s the question?????
Answer:
20%
Step-by-step explanation:
7000-5600=1400
1400/7000×100=20
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.
Answer: x=-17
Step-by-step explanation: Divide by -1 then add 8 to both sides and get (x+9)^3=-512, and the cube root of -512 is -8, so x+9=-8, and subtracting 9 from both sides we get x=-17 as answer.