Answer:
![\left[\begin{array}{ccc}3&-1&\\-1&1/2\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%26-1%26%5C%5C-1%261%2F2%5C%5C%5Cend%7Barray%7D%5Cright%5D)
Step-by-step explanation:
The matrix system for the linear equations: x + 2y = 8, 2x + 6y = 9
![\left[\begin{array}{ccc}1&2&\\2&6\\\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}8\\9\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%262%26%5C%5C2%266%5C%5C%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D8%5C%5C9%5Cend%7Barray%7D%5Cright%5D)
To get the coefficient of x and y, the inverse of the first matrix (let the first matrix be A) must be known.
= (1 / determinant of A) x Adjoint of A
the determinant of A = (1 x 6) - (2 x 2) = 6 - 4 = 2
Adjoint of A = ![\left[\begin{array}{ccc}6&-2&\\-2&1\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D6%26-2%26%5C%5C-2%261%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= ![\frac{1}{2} \left[\begin{array}{ccc}6&-2\\-2&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D6%26-2%5C%5C-2%261%5Cend%7Barray%7D%5Cright%5D)
=
Answer:
0.070
Step-by-step explanation:
Y = number on trial
Y has a negative binomial distribution
r = 3
P = 30% = 0.3 probability of positive indication.
P(Y = 11) probability of 11 employees that must be tested to get 3 positives
Y-1Cr-1*p^r*q^(y-r)
Y-1 = 11-1 = 10
r-1 = 3 -1 = 2
10C2 x 0.3³x0.7⁸
45x0.027x0.05764801
= 0.070
This is the probability that 11 employees must be tested to get 3 positives.
The answer will be arithmetic sequence!
150750 × 100100 = 20100 = 20%
If you are using a calculator, simply enter 150÷750×100 which will give you 20 as the answer.
Answer:
you can solve problems by this equation
