x+2y-3z= -1/3,xyz=2,求3/2x^2 yz+3xy^2-9/2xyz^2的值

先化简再求值3xyz+2(x^2y+y^2z-xyz)-xyz+2z^2x x=1 y= -1 z=2 先化简,再求值：3xyz+2(x²y+y²z-xyz)-xyz+2z²x,其中x=1、y=-1、z=2; xyz-【2xy-（3xyz-yz）+4xyz】,其中x=2,y=-1/2,z=-1 xyz-【2xy-（3xyz-yz）+4xyz】,其中x=2,y=-1/2,z=-1 3x^2y-[2x^2y-(2xyz-x^2z)-4x^2z]-xyz ,其中x=-2,y=-3,z=1 X^2Y-[-X^2Y+(XYZ-X^2Z)+XYZ]-X^2Z,其中x=-1,y=-2,z=1/3 3x²y-[2x²y-(2xyz-x²z)-4x²z]-xyz,其中x=-2 y=-3 z=1 xyz=1,求证：x/(1+y)+y/(1+z)+z/(1+x) >=3/2 若xyz=1,求证 x^2/(y+z)+y^2/(z+x)+z^2/(x+y)≥3/2 x^2y--[-x^2y-(2XYZ-X^2Z-3x^2y)-4x^2z]-XYZ其中x=-3,y=2,z=-1x^2y--[-x^2y-(2XYZ-X^2Z-3x^2y)-4x^2z]-XYZ其中x=-3,y=2,z=-1 (2x^3-xyz)-2(x^3-y^3+xyz)+(xyz-2y^3),其中x=-1,y=-2,z=-3. (2x³-xyz）-2（x³-y³+xyz）+（xyz-3y³） x=1 y=-2 z=-3 化简求值：（2x³-xyz)-2(x³-y³+xyz)+(xyz-2y³）,x=1,y=2,z=-3 x+y+z+2=xyz,x,y,z.为正实数,证明：xyz(x-1)(y-1)(z-1) 已知实数xyz满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3求x+y+z的值 已知x,y,z都是正数,且xyz=1,求证：x^2/(y+z)+y^2/(x+z)+z^2/(x+y)≥3/2 xyz>0,x+3y+4z=6.,x^2y^3z最值 2x+3y+4z,xyz