Question 865901
{{{(matrix(3,3,3,-4,2,1,5,-3,5,3,-1))*(matrix(3,1,x,y,z))=(matrix(3,1,-8,-2,-6))}}}
{{{A=(matrix(3,3,3,-4,2,
                 1,5,-3,
                 5,3,-1))}}}
{{{abs(A)=24}}}
.
.

{{{A[x]=(matrix(3,3,-8,-4,2,
                 -2,5,-3,
                 -6,3,-1))}}}
{{{abs(A[x])=-48}}}
.
.

{{{x=abs(A[x])/abs(A)}}}
{{{x=-48/24=-2}}}