iran-konkur 2019 Q131

iran-konkur · Other · konkur-riazi_1398_specialized_new-curriculum Matrices Linear System and Inverse Existence
131- If $A = \begin{bmatrix} 2 & 1 \\ 4 & 2 \end{bmatrix}$, from the relation $AX = A - 2I$, matrix $X$ is which of the following?
(1) $\begin{bmatrix} -2 & 2 \\ 3 & -1 \end{bmatrix}$ (2) $\begin{bmatrix} -2 & 1 \\ 4 & -1 \end{bmatrix}$ (3) $\begin{bmatrix} 2 & -1 \\ 4 & 2 \end{bmatrix}$ (4) $\begin{bmatrix} 1 & 2 \\ 4 & -1 \end{bmatrix}$
\textbf{131-} If $A = \begin{bmatrix} 2 & 1 \\ 4 & 2 \end{bmatrix}$, from the relation $AX = A - 2I$, matrix $X$ is which of the following?

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(1) $\begin{bmatrix} -2 & 2 \\ 3 & -1 \end{bmatrix}$ \hfill (2) $\begin{bmatrix} -2 & 1 \\ 4 & -1 \end{bmatrix}$ \hfill (3) $\begin{bmatrix} 2 & -1 \\ 4 & 2 \end{bmatrix}$ \hfill (4) $\begin{bmatrix} 1 & 2 \\ 4 & -1 \end{bmatrix}$

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