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.
To solve, we will follow the steps below:
3x+y=11 --------------------------(1)
5x-y=21 ------------------------------(2)
since y have the same coefficient, we can eliminate it directly by adding equation (1) and (2)
adding equation (1) and (2) will result;
8x =32
divide both-side of the equation by 8
x = 4
We move on to eliminate x and then solve for y
To eliminate x, we have to make sure the coefficient of the two equations are the same.
We can achieve this by multiplying through equation (1) by 5 and equation (2) by 3
The result will be;
15x + 5y = 55 ----------------------------(3)
15x - 3y =63 --------------------------------(4)
subtract equation (4) from equation(3)
8y = -8
divide both-side of the equation by 8
y = -1
Answer:
Why do you talk with the other people so much???
Step-by-step explaWnation:
Answer:
b 8 hours
Step-by-step explanation:
1/4 is 2 so 2/4 is 4 and we know 3/4 is 6 so 4/4 is 8 which is the answer
