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Question
Given: x + 2y = 1
3x + y = 4
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Solution
\[D = \begin{vmatrix}1 & 2 \\ 3 & 1\end{vmatrix} = - 5\]
\[ D_1 = \begin{vmatrix}1 & 2 \\ 4 & 1\end{vmatrix} = - 7\]
\[ D_2 = \begin{vmatrix}1 & 1 \\ 3 & 4\end{vmatrix} = 1\]
\[Now, \]
\[x = \frac{D_1}{D} = \frac{7}{5}\]
\[y = \frac{D_2}{D} = - \frac{1}{5}\]
\[ \therefore x = \frac{7}{5}\text{ and }y = - \frac{1}{5}\]
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