问题标题:
【已知x(x-1)-(x²-y)=-2,求(x²y²)/2-xy的值】
问题描述:
已知x(x-1)-(x²-y)=-2,求(x²y²)/2-xy的值
汪晓岩回答:
去括号,x²-x-x²+y=-2
化简,得-x+y=-2
两边乘以-1,得:x-y=2
(x²+y²)/2-xy
=(x²-2xy+y²)/2(通分)
=(x-y)²/2
=(2)²/2
=2
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已知x(x-1)-(x²-y)=-2,求(x²y²)/2-xy的值