If the system of linear equations $2 x + y - z = 7$ $x - 3 y + 2 z = 1$ $x + 4 y + \delta z = k$, where $\delta , k \in R$ has infinitely many solutions, then $\delta + k$ is equal to (1) $- 3$ (2) 3 (3) 6 (4) 9
If the system of linear equations\\
$2 x + y - z = 7$\\
$x - 3 y + 2 z = 1$\\
$x + 4 y + \delta z = k$, where $\delta , k \in R$\\
has infinitely many solutions, then $\delta + k$ is equal to\\
(1) $- 3$\\
(2) 3\\
(3) 6\\
(4) 9