约分:x的平方-y的平方除以(x-y)的平方
问题描述:
约分:x的平方-y的平方除以(x-y)的平方
通分:x除以a(x+2)与y除以b(x+2)
答
解
(x²-y²)/(x-y)²
=(x-y)(x+y)/(x-y)²
=(x+y)/(x-y)
x/a(x+2)与y/b(x+2)
∵最简公分母为ab(x+2)
∴x/a(x+2)=xb/ab(x+2)
y/b(x+2)=ya/ab(x+2)约分:x的平方+xy除以(x+y)的平方通分:2xy除以(x+y)的平方与x除以x的平方-y的平方(x²+xy)/(x+y)²=x(x+y)/(x+y)²=x/(x+y)2xy/(x+y)²x/(x²-y²)∵最简公分母为:(x+y)²(x-y)∴2xy/(x+y)²=2xy(x-y)/(x+y)²(x-y) x/(x²-y²)=x(x+y)/(x+y)²(x-y)不要两个人都追问,谢谢