Answer:
![A^{-1}=\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}](https://tex.z-dn.net/?f=A%5E%7B-1%7D%3D%5Cbegin%7Bbmatrix%7D1%20%26%202%5C%5C%20-4%20%26%20-7%5Cend%7Bbmatrix%7D)
Step-by-step explanation:
![A=\begin{bmatrix}-7 & -2\\ 4 & 1\end{bmatrix}](https://tex.z-dn.net/?f=A%3D%5Cbegin%7Bbmatrix%7D-7%20%26%20-2%5C%5C%204%20%26%201%5Cend%7Bbmatrix%7D)
![det\ A=-7\times 1-(-2)\times 4\\\Rightarrow det\ A=1](https://tex.z-dn.net/?f=det%5C%20A%3D-7%5Ctimes%201-%28-2%29%5Ctimes%204%5C%5C%5CRightarrow%20det%5C%20A%3D1)
![A^{-1}=\frac{1}{det\ A}\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}\\\Rightarrow A^{-1}=\frac{1}{1}\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}\\\Rightarrow A^{-1}=\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}](https://tex.z-dn.net/?f=A%5E%7B-1%7D%3D%5Cfrac%7B1%7D%7Bdet%5C%20A%7D%5Cbegin%7Bbmatrix%7D1%20%26%202%5C%5C%20-4%20%26%20-7%5Cend%7Bbmatrix%7D%5C%5C%5CRightarrow%20A%5E%7B-1%7D%3D%5Cfrac%7B1%7D%7B1%7D%5Cbegin%7Bbmatrix%7D1%20%26%202%5C%5C%20-4%20%26%20-7%5Cend%7Bbmatrix%7D%5C%5C%5CRightarrow%20A%5E%7B-1%7D%3D%5Cbegin%7Bbmatrix%7D1%20%26%202%5C%5C%20-4%20%26%20-7%5Cend%7Bbmatrix%7D)
![\therefore A^{-1}=\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}](https://tex.z-dn.net/?f=%5Ctherefore%20A%5E%7B-1%7D%3D%5Cbegin%7Bbmatrix%7D1%20%26%202%5C%5C%20-4%20%26%20-7%5Cend%7Bbmatrix%7D)
![A.A^{-1}=\begin{bmatrix}-7 & -2\\ 4 & 1\end{bmatrix}\times \begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}\\\Rightarrow A.A^{-1}=\begin{pmatrix}\left(-7\right)\cdot \:1+\left(-2\right)\left(-4\right)&\left(-7\right)\cdot \:2+\left(-2\right)\left(-7\right)\\ 4\cdot \:1+1\cdot \left(-4\right)&4\cdot \:2+1\cdot \left(-7\right)\end{pmatrix}\\\Rightarrow A.A^{-1}=\begin{pmatrix}1&0\\ 0&1\end{pmatrix}](https://tex.z-dn.net/?f=A.A%5E%7B-1%7D%3D%5Cbegin%7Bbmatrix%7D-7%20%26%20-2%5C%5C%204%20%26%201%5Cend%7Bbmatrix%7D%5Ctimes%20%5Cbegin%7Bbmatrix%7D1%20%26%202%5C%5C%20-4%20%26%20-7%5Cend%7Bbmatrix%7D%5C%5C%5CRightarrow%20A.A%5E%7B-1%7D%3D%5Cbegin%7Bpmatrix%7D%5Cleft%28-7%5Cright%29%5Ccdot%20%5C%3A1%2B%5Cleft%28-2%5Cright%29%5Cleft%28-4%5Cright%29%26%5Cleft%28-7%5Cright%29%5Ccdot%20%5C%3A2%2B%5Cleft%28-2%5Cright%29%5Cleft%28-7%5Cright%29%5C%5C%204%5Ccdot%20%5C%3A1%2B1%5Ccdot%20%5Cleft%28-4%5Cright%29%264%5Ccdot%20%5C%3A2%2B1%5Ccdot%20%5Cleft%28-7%5Cright%29%5Cend%7Bpmatrix%7D%5C%5C%5CRightarrow%20A.A%5E%7B-1%7D%3D%5Cbegin%7Bpmatrix%7D1%260%5C%5C%200%261%5Cend%7Bpmatrix%7D)
Hence, confirmed
<span>4 times the difference of n and 8
=4(n-8)</span>
Answer:
(8 x 8)= 64 x 18 = 1,152 in
Step-by-step explanation:
I think that is that answer
Answer:
1/4
Step-by-step explanation:
10+10+20=40
10 of those are red cards which makes it 10/40 which is simplified to 1/4.
If it is a multiple choice, the answers are B and D.
If it is not a multiple choice, the answer is B.
Best of luck.