Question 809282
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