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If ∣ ∣ ∣ X + 1 X − 1 X − 3 X + 2 ∣ ∣ ∣ = ∣ ∣ ∣ 4 − 1 1 3 ∣ ∣ ∣ , Then Write the Value of X. - Mathematics

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Question

If \[\begin{vmatrix}x + 1 & x - 1 \\ x - 3 & x + 2\end{vmatrix} = \begin{vmatrix}4 & - 1 \\ 1 & 3\end{vmatrix}\], then write the value of x.
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Solution

\[\begin{vmatrix}x + 1 & x - 1 \\ x - 3 & x + 2\end{vmatrix} = \begin{vmatrix}4 & - 1 \\ 1 & 3\end{vmatrix}\] 
\[ \Rightarrow \left( x + 1 \right)\left( x + 2 \right) - \left( x - 1 \right)\left( x - 3 \right) = 12 + 1\] 
\[ \Rightarrow x^2 + 3x + 2 - x^2 + 4x - 3 = 13\] 
\[ \Rightarrow 7x - 1 = 13\] 
\[ \Rightarrow 7x = 14\] 
\[ \Rightarrow x = 2\] 
Hence, the value of x is 2 .

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Chapter 6: Determinants - Exercise 6.6 [Page 92]

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RD Sharma Mathematics [English] Class 12
Chapter 6 Determinants
Exercise 6.6 | Q 45 | Page 92

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