find the values of $a$ and $b$ for which the following system is consistent
$x+ y-z+w=1$
$ax+y+z+w=b$
$3x+2y+aw=1+a$
Note: I have been using gauss elimination, but I got confused when completed "power-1" in the 3rd line
how to move in column 4?
I feel the value that can be entered is a $2$ and $a=1$, but I do not have proof for that