题目内容
先化简,再求值:[(x﹣y)2+(x﹣y)(x+y)]÷x,其中x=﹣1,y=
解:[(x﹣y)2+(x﹣y)(x+y)]÷x,
=(x2﹣2xy+y2+x2﹣y2)÷x,
=(2x2﹣2xy)÷x,
=2x﹣2y,
当x=﹣1,y=
,
原式=2×(﹣1)﹣2×
=﹣3.
=(x2﹣2xy+y2+x2﹣y2)÷x,
=(2x2﹣2xy)÷x,
=2x﹣2y,
当x=﹣1,y=
原式=2×(﹣1)﹣2×
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