If inverse of the matrix $\left[\begin{array}{cc}2 & -0.5 \ -1 & x\end{array}\right]$ is $\left[\begin{array}{ll}1 & 1 \ 2 & 4 \end{array}\right]$, then the value of $x$ is

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A - $0.5$. A*A^(-1) = I: row 2 of A times column 1 of inverse: -1*1 + 2x = 0 gives x = 0.5 (other entries check: -1 + 4x = 1).

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B - $1$

Answer

C - $2$

Answer

D - $3$

If inverse of the matrix \(\left[\begin{array}{cc}2 & -0.5 \\ -1 & x\end{array}\right]\) is \(\left[\begin{array}{ll}1 & 1 \\ 2 & 4 \end{array}\right]\), then the value of \(x\) is

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