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Without Expanding, Show that the Value of the Following Determinant is Zero: ∣ ∣ ∣ ∣ 49 1 6 39 7 4 26 2 3 ∣ ∣ ∣ ∣ - Mathematics

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Question

Without expanding, show that the value of the following determinant is zero:

\[\begin{vmatrix}49 & 1 & 6 \\ 39 & 7 & 4 \\ 26 & 2 & 3\end{vmatrix}\]

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Solution

\[ ∆ = \begin{vmatrix}49 & 1 & 6 \\ 39 & 7 & 4 \\ 26 & 2 & 3\end{vmatrix}\]
\[ = \begin{vmatrix}1 & 1 & 6 \\ 7 & 7 & 4 \\ 2 & 2 & 3\end{vmatrix} \left[ \text{ Applying } C_1 \to C_1 - 8 C_3 \right]\]
\[ \Rightarrow ∆ = 0\]

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Chapter 6: Determinants - Exercise 6.2 [Page 57]

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RD Sharma Mathematics [English] Class 12
Chapter 6 Determinants
Exercise 6.2 | Q 2.07 | Page 57

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