分式的通分 基础题

1/(x^2-y^2)=1/[(x+y)(x-y)]
1/(x^2+xy)=1/[x(x+y)]
最简公分母为x(x+y)(x-y)
1/(x^2-y^2)=x/[x(x+y)(x-y)]
1/(x^2+xy)=(x-y)/[x(x+y)(x-y)]

各个分母求最小公倍数
即提出共因子(x+y) 在分别乘上各自特有的因子
(x-y)和x

1/x(x+y)(x-y)
1/x^2-y^2=1/(x+y)(x-y)
1/x^2+xy= 1/x(x+y)