In the matrix, the first row is exactly twice the second. This implies that the determinant is zero.
If the matrix system has determinant zero, the system has either no solutions or infinite solutions.
However, just like in the matrix, in the constant vector the first term is twice the second. This means that the system has infinite solutions.
In fact, if you write this system in expanded form, you can see that it generates two equations, the first being twice the second:
[tex]\begin{cases}2x+4y=6\\x+2y=3\end{cases}[/tex]
