Question 1093276
{{{4x+A=x}}}
{{{-3x=A}}}
{{{x=A/(-3)}}}
So,
{{{A=(matrix(1,3,6,-3,9))}}}
{{{A/(-3)=(matrix(1,3,6/(-3),-3/(-3),9/(-3)))}}}
{{{A/(-3)=(matrix(1,3,-2,1,-3))}}}