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If P=114[32−42]P = \dfrac{1}{14}\begin{bmatrix} 3 & 2 \\ -4 & 2 \end{bmatrix} and P−1=[x−24y]P^{-1} = \begin{bmatrix} x & -2 \\ 4 & y \end{bmatrix}, then the value of xx and yy respectively are

Solution

✅ Correct Option: 4

∣P∣=1142(3⋅2−2⋅(−4))=14196=114|P|=\dfrac{1}{14^2}(3\cdot 2-2\cdot(-4))=\dfrac{14}{196}=\dfrac{1}{14}.

P−1=14⋅114[2−243]=[2−243]P^{-1}=14\cdot\dfrac{1}{14}\begin{bmatrix}2&-2\\4&3\end{bmatrix}=\begin{bmatrix}2&-2\\4&3\end{bmatrix}.

Comparing, x=2x=2, y=3y=3.

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