Question 1062932
{{{A=(matrix(3,4,
1,2,3,9,
2,-1,1,8,
1,0,-1,3))}}}
Add {{{R[2]}}} and {{{R[3]}}} and replace in {{{R[3]}}},
{{{A=(matrix(3,4,
1,2,3,9,
2,-1,1,8,
5,-1,0,11))}}}
Replace {{{R[2]}}} with {{{R[1]-3R[2]}}},
{{{A=(matrix(3,4,
1,2,3,9,
-5,5,0,-15,
5,-1,0,11))}}}
Replace {{{R[3]}}} with {{{R[2]+5R[3]}}},
{{{A=(matrix(3,4,
1,2,3,9,
-5,5,0,-15,
20,0,0,40))}}}
So then from {{{R[3]}}},
{{{20x=40}}}
{{{x=2}}}
Then from {{{R[2]}}}
{{{-5(2)+5y=-15}}}
{{{5y=-5}}}
{{{y=-1}}}
and then from {{{R[1]}}},
{{{2+2(-1)+3z=9}}}
{{{3z=9}}}
{{{z=3}}}