Answer:
3575880
Step-by-step explanation:
We need to use Permutation method,

Where n is the sample of size and r the combination considered, so

There is 3575880 possibilities to make leadership structures in that committee
Answer:
The total number of U.S. high school students that played on a sports team that year can be estimated to be 7,950,000.
Step-by-step explanation:
From the random sample, we can expect that
of all students played on a sports team that year. So in the bigger sample of 15900000 high school students, we can expect
students to have played on a sports team that year.
Answer:
The correct answer is 
Step-by-step explanation:
I believe the answer to this is C. English.
Quadratic equation is

WHEN

So, to make this true subtract 7 from each side.
The equation is now
7

- x - 7 = 0
Values for a, b, and c: a = 7, b = -1, c = -7
Plug these variables into the quadratic equation.
Square -1 to get 1 and multiply -4 x 7 x -7 to get 196.

Multiply 2 x -7 to get -14, the denominator, and add 1 to 196.
Since 197 is not a square number, and I don't know if you want to leave it in radical form or not, I will just because it's easier to understand.
Hope this helps!