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Without Expanding, Show that the Value of the Following Determinant is Zero: ∣ ∣ ∣ ∣ 2 3 7 13 17 5 15 20 12 ∣ ∣ ∣ ∣ - Mathematics

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Question

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

\[\begin{vmatrix}2 & 3 & 7 \\ 13 & 17 & 5 \\ 15 & 20 & 12\end{vmatrix}\]

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Solution

\[ ∆ = \begin{vmatrix}2 & 3 & 7 \\ 13 & 17 & 5 \\ 15 & 20 & 12\end{vmatrix}\]
\[ = \begin{vmatrix}2 & 3 & 7 \\ 13 & 17 & 5 \\ 13 & 17 & 5\end{vmatrix} \left[ \text{ Applying } R_3 \to R_3 - R_1 \right]\]
\[ \Rightarrow ∆ = 0\]

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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 2.03 | Page 57

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