Question

2x − y = 5
4x − 2y = 7

Answer 1

Given: 2x − y = 5
            4x − 2y = 7

\[D = \begin{vmatrix}2 & - 1 \\ 4 & - 2\end{vmatrix} = - 4 + 4 = 0\] 
\[ D_1 = \begin{vmatrix}5 & - 1 \\ 7 & - 2\end{vmatrix} = - 10 + 7 = - 3\] 
\[ D_{2 =} \begin{vmatrix}2 & 5 \\ 4 & 7\end{vmatrix} = 14 - 20 = - 6\]
Here, D₁ and D₂ are non-zero, but D is zero. Thus, the given system of linear equations is inconsistent.