急！！！！！！ 帮帮忙！！！！ T^T 数学。！
1个回答
展开全部
①(x²+y²)/(x-y)-2xy/(x-y)
=(x²+y²-2xy)/(x-y)
=(x-y)²/(x-y)
=x-y
②a²/(a+1)-1/(a+1)
=(a²-1)/(a+1)
=(a+1)(a-1)/(a+1)
=a-1
❸2/(x²-9)÷1/(x-3)
=2/(x-3)(x+3)×(x-3)
=2/(x+3)
=(x²+y²-2xy)/(x-y)
=(x-y)²/(x-y)
=x-y
②a²/(a+1)-1/(a+1)
=(a²-1)/(a+1)
=(a+1)(a-1)/(a+1)
=a-1
❸2/(x²-9)÷1/(x-3)
=2/(x-3)(x+3)×(x-3)
=2/(x+3)
本回答由网友推荐
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
