3x^2y-[2x^2y-(2xyz-x^2y)-4x^2z-xyz],其中x=-2,y=-3,z=1
先化简,再求值.
人气：377 ℃ 时间：2020-01-27 15:11:53
解答
3x^2y-[2x^2y-(2xyz-x^2y)-4x^2z-xyz]=3x^2y-(2x^2y-2xyz+x^2y-4x^2z-xyz)=3x^2y-2x^2y+2xyz-x^2y+4x^2z+xyz=3x^2y-2x^2y-x^2y+2xyz+xyz+4x^2z=3xyz+4x^2z=3×（-2）×（-3）×1+4×（-2）^2×1=18+16=34
推荐
猜你喜欢
