把x2-y2+2y-1分解因式结果正确的是()A.(x+y+1)(x-y-1)B.(x+y-1)(x-y+1)C.(x+y-1)(x+y+1)D.(x-y+1)(x+y+1)-数学

题目简介

把x2-y2+2y-1分解因式结果正确的是()A.(x+y+1)(x-y-1)B.(x+y-1)(x-y+1)C.(x+y-1)(x+y+1)D.(x-y+1)(x+y+1)-数学

题目详情

把x2-y2+2y-1分解因式结果正确的是(  )
A.(x+y+1)(x-y-1)B.(x+y-1)(x-y+1)C.(x+y-1)(x+y+1)D.(x-y+1)(x+y+1)
题型:单选题难度:偏易来源:不详

答案

原式=x2-(y2-2y+1)
=x2-(y-1)2
=(x+y-1)(x-y+1),
故选B.

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