若x=100,y=99,求(x-y+4xy/x-y)(x+y-4xy/x+y) 浏览次数:3Q
问题描述:
若x=100,y=99,求(x-y+4xy/x-y)(x+y-4xy/x+y) 浏览次数:3Q
答
(X-y+4xy/x-y)(x+y-4xy/x+y)=[(X-Y)^+4XY/(X-Y)][(X+Y)^-4XY/(X+Y)]=[(X+Y)^/(X-Y)][(X-Y)^/(X+Y)]=(X+Y)(X-Y)=199
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