已知(x+2)²+|x+y+5|=0,求3x²y+{-2x²y-[-2xy+(x²y-4x²)]-xy}的值
已知(x+2)²+|x+y+5|=0,求3x²y+{-2x²y-[-2xy+(x²y-4x²)]-xy}的值
更新时间:2024-04-25 21:23:13
问题描述:
已知(x+2)²+|x+y+5|=0,求3x²y+{-2x²y-[-2xy+(x²y-4x²)]-xy}的值
x+2=0x=-2x+y+5=03+y=0y=-33x^2y+{-2x^2y-[-2xy+(x^2y-4x^2)]-xy}=3x^2y+{-2x^2y-[-2xy+x^2y-4x^2]-xy}=3x^2y+{-2x^2y+2xy-x^2y+4x^2-xy}=3x^2y-2x^2y+2xy-x^2y+4x^2-xy=xy+4x^2把x=-2,y=-3代入xy+4x^2.-2×-3+...
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