Describe all solutions of the system:
$-x_1 + 2x_2 + x_3 + 4x_4 = 0$
$2x_1 + x_2 -x_3 +x_4 = 1$
I solved and got:
$\langle x_1, x_2, x_3, x_4\rangle = \langle x_3 +2x_4 + 2, x_3 +9x_4 - 1, x_3, x_4 \rangle$
$= x_3\langle 1, 1, 1, 0\rangle + x_4\langle 2, 9, 0, 1\rangle + \langle 2, -1, 0, 0\rangle$
How do I check my solution and what does my solution mean?