MCQ
If $\text{A}=\displaystyle \begin{vmatrix} 2 &\text{amp;}-3 \\ 3 &\text{amp; 2} \end{vmatrix}$ and $\text{B}=\displaystyle \begin{vmatrix} 3 &\text{amp;}-2 \\ 2 &\text{amp; 3} \end{vmatrix}$ then $2\text{ A-B}=$
  • A
    $\displaystyle \begin{vmatrix} 1 &4 \\ 4 &1\end{vmatrix}$
  • B
    $\displaystyle \begin{vmatrix} 1 &4 \\ 1 &4\end{vmatrix}$
  • $\displaystyle \begin{vmatrix} 1 &-4 \\ 4 &1\end{vmatrix}$
  • D
    $\displaystyle \begin{vmatrix} 4 &1\\ 1 &4\end{vmatrix}$

Answer

Correct option: C.
$\displaystyle \begin{vmatrix} 1 &-4 \\ 4 &1\end{vmatrix}$
$2\text{ A-B}=\displaystyle \begin{vmatrix} 4 &\text{amp;}-6 \\ 6 &\text{amp; 4} \end{vmatrix}-\displaystyle \begin{vmatrix} 3 &\text{amp;}-2 \\ 2 &\text{amp; 3} \end{vmatrix}$
$=\displaystyle \begin{vmatrix} 1 &\text{amp;}-4\\ 4 &\text{amp; 1} \end{vmatrix}$

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