分解因式:xy方-x 计算:ab分之a方-b方÷(a分之1-b分之1)
问题描述:
分解因式:xy方-x 计算:ab分之a方-b方÷(a分之1-b分之1)
答
xy²-x
=x(y²-1)
=x(y+1)(y-1)
[(a²-b²)/(ab)]÷(1/a-1/b)
=[(a+b)(a-b)/(ab)]÷[-(a-b)/(ab)]
=[(a+b)(a-b)/(ab)]×[-ab/(a-b)]
=-a-b