You can put this solution on YOUR website! x=-4.77335, y=0.0600211, z=10.54
Are you sure you copied it correctly?
-x4y+4z=11
It doesn't look right to me.
perhaps
-x+4y+4z=11
x = 157/5, y = -271/5, z = 324/5
or
-x-4y+4z=11
x = -441/55, y = 271/55, z = 312/55