The solution of the linear system $$\begin{array}{rrrrcr} w &+2x &+3y &-4z &=& -5 \\ 2w&-x &+y &-2z &=& -7 \\ 3w&-x &-2y &+z&=& 7 \\ 4w&-4x &-2y &+3z&=& 3 \\ \end{array}$$ The solution of this system is
$w=$ , $x=$ , $y=$ , and $z=$ .