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If [3121]P[2132]=[1−101]\begin{bmatrix}3 & 1\\2 & 1\end{bmatrix}P\begin{bmatrix}2 & 1\\3 & 2\end{bmatrix}=\begin{bmatrix}1 & -1\\0 & 1\end{bmatrix} then matrix P is

Solution

✅ Correct Option: 3

Write APB=CAPB=C, so P=A−1CB−1P=A^{-1}CB^{-1}.

Both AA and BB have determinant 11, so A−1=[1−1−23]A^{-1}=\begin{bmatrix}1&-1\\-2&3\end{bmatrix} and B−1=[2−1−32]B^{-1}=\begin{bmatrix}2&-1\\-3&2\end{bmatrix}.

A−1C=[1−2−25]A^{-1}C=\begin{bmatrix}1&-2\\-2&5\end{bmatrix}, and multiplying by B−1B^{-1} gives P=[8−5−1912]P=\begin{bmatrix}8&-5\\-19&12\end{bmatrix}.

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