若x,y为实数,且y=1-4x+4x-1+12.求xy+2+yx-xy-2+yx 发布时间:2017-04-16 23:42 │ 来源:www.tikuol.com 题型:解答题 问题: 若x,y为实数,且y=1-4x+4x-1+12.求xy+2+yx-xy-2+yx的值.
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