数学分式通分与约分约分 (x²+xy)/(x+y)² x²-y²/（x²

约分
(x²+xy)/(x+y)²
=x(x+y)/(x+y)²
=x/(x+y）
x²-y²/（x²-y²）=1
通分
2xy/(x+y)²与x/x²-y²
2xy/(x+y)²=2xy(x-y)/[(x+y)²（x-y）]
x/(x²-y²)=x(x+y)/[(x+y)²(x-y)]
x-y/2x+2y与xy/(x+y)²
(x-y)/(2x+2y)=(x-y)(x+y)[2(x+y)²]=（x²-y²)/[2(x+y)²]
xy/(x+y)²=2xy/[2(x+y)²]
再问： x²-y²/（x-y）² 约分zm uzo !
再答： (x²-y²)/(x-y)² =(x-y)(x+y)/(x-y)² =(x+y)/(x-y)