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# The inverse of matrix N = $$\begin{vmatrix} 2 & 3 \\ 1 & 4\end{vmatrix}$$ is

### Question

The inverse of matrix N = $$\begin{vmatrix} 2 & 3 \\ 1 & 4\end{vmatrix}$$ is

### Options

A) $$\frac{1}{5}$$ $$\begin{vmatrix} 2 & 1 \\ 3 & 4\end{vmatrix}$$

B) $$\frac{1}{5}$$ $$\begin{vmatrix} 4 & -3 \\ -1 & 2\end{vmatrix}$$

C) $$\frac{1}{5}$$ $$\begin{vmatrix} 2 & -1 \\ -3 & 4\end{vmatrix}$$

D) $$\frac{1}{5}$$ $$\begin{vmatrix} 4 & 3 \\ 1 & 2\end{vmatrix}$$

### Explanation:

N = [2 3]
N-1 = $$\frac{adj N}{|N|}$$
adj N = $$\begin{vmatrix} 4 & -3 \\ -1 & 2 \end{vmatrix}$$
|N| = (2 x4) - (1 x 3)
= 8 - 3
=5
N-1 = $$\frac {1}{5}$$ $$\begin{vmatrix} 4 & -3 \\ -1 & 2 \end{vmatrix}$$

## Dicussion (1)

• N = [2 3]
N-1 = $$\frac{adj N}{|N|}$$
adj N = $$\begin{vmatrix} 4 & -3 \\ -1 & 2 \end{vmatrix}$$
|N| = (2 x4) - (1 x 3)
= 8 - 3
=5
N-1 = $$\frac {1}{5}$$ $$\begin{vmatrix} 4 & -3 \\ -1 & 2 \end{vmatrix}$$