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Find the Value of X, If ∣ ∣ ∣ 2 4 5 1 ∣ ∣ ∣ = ∣ ∣ ∣ 2 X 4 6 X ∣ ∣ - Mathematics

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Question

Find the value of x, if
\[\begin{vmatrix}2 & 4 \\ 5 & 1\end{vmatrix} = \begin{vmatrix}2x & 4 \\ 6 & x\end{vmatrix}\]

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Solution

\[\text{ Given }: \hspace{0.167em} \begin{vmatrix}2 & 4 \\ 5 & 1\end{vmatrix} = \begin{vmatrix}2x & 4 \\ 6 & x\end{vmatrix}\]
\[ \Rightarrow 2 - 20 = 2 x^2 - 24\]
\[ \Rightarrow - 18 = 2 x^2 - 24\]
\[ \Rightarrow 2 x^2 = 6\]
\[ \Rightarrow x^2 = 3\]
\[ \Rightarrow x = \pm \sqrt{3}\]

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Chapter 6: Determinants - Exercise 6.1 [Page 10]

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RD Sharma Mathematics [English] Class 12
Chapter 6 Determinants
Exercise 6.1 | Q 10.1 | Page 10

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