通分a/a+b和b/a-b

问题描述:

通分a/a+b和b/a-b

a/a+b=a(a-b)/(a+b)(a-b)=(a²-ab)/(a²-b²)
b/a-b=b(a+b)/(a-b)(a+b)=(ab+b²)/(a²-b²)

a/(a+b)=a(a-b)/(a-b)(a+b)
b/(a-b)=b(a+b)/(a-b)(a+b)