Question 1020897
Use Cramer's rule,
{{{A=(matrix(4,4,
3,0,0,-2,
0,2,-2,1,
-3,3,-2,2,
6,1,0,1))}}}
{{{abs(A)=36}}}
.
.
.
{{{A[x1]=(matrix(4,4,
1,0,0,-2,
2,2,-2,1,
3,3,-2,2,
4,1,0,1))}}}
{{{abs(A[x1])=12}}}
.
.
.
{{{A[x2]=(matrix(4,4,
3,1,0,-2,
0,2,-2,1,
-3,3,-2,2,
6,4,0,1))}}}
{{{abs(A[x2])=72}}}
.
.
.
{{{A[x3]=(matrix(4,4,
3,0,1,-2,
0,2,2,1,
-3,3,3,2,
6,1,4,1))}}}
{{{abs(A[x3])=36}}}
.
.
.
{{{A[x4]=(matrix(4,4,
3,0,0,1,
0,2,-2,2,
-3,3,-2,3,
6,1,0,4))}}}
{{{abs(A[x4])=0}}}
.
.
.
{{{x[1]=abs(A[x1])/abs(A)=12/36=1/3}}}
{{{x[2]=abs(A[x2])/abs(A)=72/36=2}}}
{{{x[3]=abs(A[x3])/abs(A)=36/36=1}}}
{{{x[4]=abs(A[x4])/abs(A)=0/36=0}}}