15分[图]一道数学化简求值题地址:http://hi.baidu.com/shmily%C6%E6%D2%D5%B9%FB/album/item/9105dc18f63a686d42a9ad1d.html如果嫌发答案过来麻烦,也可以像我这样给图,应该能看清楚吧

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15分[图]一道数学化简求值题地址:http://hi.baidu.com/shmily%C6%E6%D2%D5%B9%FB/album/item/9105dc18f63a686d42a9ad1d.html如果嫌发答案过来麻烦,也可以像我这样给图,应该能看清楚吧
15分[图]一道数学化简求值题
地址:
http://hi.baidu.com/shmily%C6%E6%D2%D5%B9%FB/album/item/9105dc18f63a686d42a9ad1d.html
如果嫌发答案过来麻烦,也可以像我这样给图,
应该能看清楚吧

15分[图]一道数学化简求值题地址:http://hi.baidu.com/shmily%C6%E6%D2%D5%B9%FB/album/item/9105dc18f63a686d42a9ad1d.html如果嫌发答案过来麻烦,也可以像我这样给图,应该能看清楚吧
用配方法.尽量在分子中配出分母的因式

=y/(x-y)+y^3/x(x+y)^2*(y-x)(y+x)/y(y+x)
=y/(x-y)+y^3/x(x+y)^2*(y-x)/y
=y/(x-y)+y^2(y-x)/x(x+y)^2
=[yx(x+y)^2-y^2(x-y)^2]/x(x+y)^2*(x-y)
=[yx^3+2x^2y^2+y^3x-x^2y^2+2xy^3-y^4]/x(x+y)^2*(...

全部展开

=y/(x-y)+y^3/x(x+y)^2*(y-x)(y+x)/y(y+x)
=y/(x-y)+y^3/x(x+y)^2*(y-x)/y
=y/(x-y)+y^2(y-x)/x(x+y)^2
=[yx(x+y)^2-y^2(x-y)^2]/x(x+y)^2*(x-y)
=[yx^3+2x^2y^2+y^3x-x^2y^2+2xy^3-y^4]/x(x+y)^2*(x-y)
=[xy(x+y)^2-y^2(x-y)^2]/x(x+y)^2*(x-y)
=y/(x-y)-y^2(x-y)/x(x+y)^2
=-4-200/9*35^2
=-1772/441
感觉不太对啊

收起

用配方法。尽量在分子中配出分母的因式