i think it is not correct Question.1)-2(x-y+z)=-2x+2y-2z=6----->2y=2x+2z+62)x+2y+z=3-------> 2y=3-x-zso that, from point 1&2, we have:2x+2z+6=3-x-z SO 3+3z+3x=0 SO x+z=-1and also we know that: x+2y+z=3so it is equal by 2y-1=3 so that y=2but we have x-y+z=6 , but here is a problem:x+z=-1 & y=2 ------> -1-2≠6