Answer:
-7j-k-1
Step-by-step explanation:
First, let me show you some notation.
To show a matrix is an inverse of another matrix, we write

-1 is not an exponent. It just shows that a matrix is an inverse of another matrix.
For a 2x2 matrix, we can get the inverse by first making b and c negatives and swap the positions of a and d.
Then multiply each entry in the matrix by 1 divided by the determinant.
![\left[\begin{array}{ccc}a&b\\c&d\end{array}\right]^{-1} = \frac{1}{ad - bc}\left[\begin{array}{ccc}d&{-b}\\{-c}&a\end{array}\right] = \\ \\ \\ \left[\begin{array}{ccc}d(\frac{1}{ad-bc})&{-b}(\frac{1}{ad-bc}) \\ {-c}(\frac{1}{ad-bc}) &a(\frac{1}{ad-bc}) \end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Da%26b%5C%5Cc%26d%5Cend%7Barray%7D%5Cright%5D%5E%7B-1%7D%20%3D%20%0A%20%20%5Cfrac%7B1%7D%7Bad%20-%20bc%7D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dd%26%7B-b%7D%5C%5C%7B-c%7D%26a%5Cend%7Barray%7D%5Cright%5D%20%3D%20%20%5C%5C%20%20%5C%5C%20%5C%5C%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dd%28%5Cfrac%7B1%7D%7Bad-bc%7D%29%26%7B-b%7D%28%5Cfrac%7B1%7D%7Bad-bc%7D%29%20%5C%5C%20%7B-c%7D%28%5Cfrac%7B1%7D%7Bad-bc%7D%29%20%26a%28%5Cfrac%7B1%7D%7Bad-bc%7D%29%20%5Cend%7Barray%7D%5Cright%5D)
I hope this helped!
Answer:

Step-by-step explanation:
The given equation is 
We want to rearrange this equation so that, n becomes the independent variable.
This means we must solve form, m which becomes the dependent variable.
We expand the parenthesis to get:

We now subtract 1 from both sides to obtain:

We simplify to obtain:

This can be rewritten as

Answer:
Step-by-step explanation:
the students that are in the survey are in it because they like the subject, rather than picking students from both types of groups, the ones that aren't doing remote learning and the ones that are doing remote learning.
Answer:
-20
Step-by-step explanation:
-3×4 is -12.
-2×4= -8
add the two, and you get -20