若|x-3|+|y+z|+|2z+1|=0,求xy-yz的值

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若|x-3|+|y+z|+|2z+1|=0,求xy-yz的值

若|x-3|+|y+z|+|2z+1|=0,求xy-yz的值
若|x-3|+|y+z|+|2z+1|=0,求xy-yz的值

若|x-3|+|y+z|+|2z+1|=0,求xy-yz的值
|x-3|+|y+z|+|2z+1|=0
则|x-3|=0 x=3
|y+z|=0 y=-z =1/2
|2z+1|=0 z=-1/2
xy-yz= 3 x 1/2 - 1/2 x(-1/2) =7/4

若|x-3|+|y+z|+|2z+1|=0
则|x-3|=|y+z|=|2z+1|=0
则x-3=y+z=2z+1=0
则x=3 z=-1/2 y=1/2
xy-yz=y(x-z)=1/2*7/2=7/4