3x²y-[2x²y-(2xyz-x²z)-4x²z]-xyz
=3x²y-(2x²y-2xyz+x²z-4x²z)-xyz
=3x²y-2x²y+2xyz-x²z+4x²z-xyz
=x²y+3x²z+xyz
当x=-2 y=-3 z=1时,
原式=(-2)²×(-3)+3×(-2)²×1+(-2)×(-3)×1
=4×(-3)+3×4×1+(-2)×(-3)×1
=-12+12+6
=6
3x²y-[2x²y-(2xyz-x²z)-4x²z]-xyz
=3x²y-(2x²y-2xyz+x²z-4x²z)-xyz
=3x²y-2x²y+2xyz-x²z+4x²z-xyz
=x²y+3x²z+xyz
当x=-2 y=-3 z=1时,
原式=(-2)²×(-3)+3×(-2)²×1+(-2)×(-3)×1
=4×(-3)+3×4×1+(-2)×(-3)×1
=-12+12+6
=6