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2x − Y = − 2 3x + 4y = 3 - Mathematics

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Question

2x − y = − 2
3x + 4y = 3

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Solution

\[\text{ Given }: 2x - y = - 2\] 
\[ 3x + 4y = 3\] 
Using Cramer's Rule, we get 
\[D = \begin{vmatrix} 2 & - 1 \\3 & 4 \end{vmatrix} = 8 + 3 = 11\] 
\[ D_1 = \begin{vmatrix} - 2 & - 1\\ 3 & 4 \end{vmatrix} = - 8 + 3 = - 5\] 
\[ D_2 = \begin{vmatrix} 2 &- 2 \\3 & 3 \end{vmatrix} = 6 + 6 = 12\] 
Now,
\[x = \frac{D_1}{D} = \frac{- 5}{11}\] 
\[y = \frac{D_2}{D} = \frac{12}{11}\] 
\[ \therefore x = - \frac{5}{11}\text{ and }y = \frac{12}{11}\]

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Chapter 6: Determinants - Exercise 6.4 [Page 84]

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RD Sharma Mathematics [English] Class 12
Chapter 6 Determinants
Exercise 6.4 | Q 5 | Page 84

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