Question 1027945
Try either Elimination Method, or row reduction operations (matrices), since so many variables.


{{{(matrix(3,4,
3,2,1,8,
2,-3,2,-16,
1,4,-1,20
))}}}



Exchange R1 and R3.
{{{(matrix(3,4,
1,4,-1,20,
2,-3,2,-16,
3,2,1,8
))}}}


R2=R2-2*R1;
R3=R3-3*R1.
----
{{{(matrix(3,4,
1,4,-1,20,
0,-11,4,-56,
0,-10,4,-52
))}}}



R2=-1*R2, R3=-1*R3.
---
{{{(matrix(3,4,
1,4,-1,20,
0,11,-4,56,
0,10,-4,52
))}}}


(1/2)*R3
{{{(matrix(3,4,
1,4,-1,20,
0,11,-4,56,
0,5,-2,26
))}}}


{{{(matrix(3,4,
1,4,-1,20,
0,55,-20,280,
0,55,-22,286)
)}}}


R3=R3-R2
---
{{{(matrix(3,4,
1,4,-1,20,
0,55,-20,280,
0,0,-2,6))}}}


R2 *(1/5)  and R3*  (-1/2)
-
{{{(matrix(3,4,
1,4,-1,20,
0,11,-4,56,
0,0,1,-3)
)}}}


This is still not finished, but at this point shows {{{z=-3}}}.
Continue with row operations, now moving upward;  Let R2=R2+4*R3; and let R1=R1+R3; and you will see the partial result indicating {{{y=whateverIsFound}}}.  Solve for x from that any way you like.