(1)∵(x+2) 2+|y+3|+(z-1) 2=0,
∴x+2=0,y+3=0,z-1=0,
∴x=-2,y=-3,z=1,
则3x 2y-{xyz-(2xyz-x 2z)-4x 2z+[3x 2y-(4xyz-5x 2z-3xyz)]}
=3x 2y-{xyz-2xyz+x 2z-4x 2z+3x 2y-4xyz+5x 2z+3xyz}
=3x 2y-{-2xyz+2x 2z+3x 2y}
=2xyz-2x 2z,
代入值得,原式=2xyz-2x 2z=12-8=4;
(2)2x 2+ax-y+6-(2bx 2-3x+5y-1)
=2x 2+ax-y+6-2bx 2+3x-5y+1
=(2-2b)x 2+(a+3)x-6y+7
∵与字母x的值无关,
∴b=1,a=-3,
则原式=-9-3-3+2=-13.