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已知x/y=5/3已知已知x/y=5/3,x/(x+y)+x/(x-y)-y^2/(x^2-y^2)求x/(x+y)+x/(x-y)-y^2/(x^2-y^2)的值。

题目详情
已知x/y=5/3
已知已知x/y=5/3,x/(x+y)+x/(x-y)-y^2/(x^2-y^2)
求x/(x+y)+x/(x-y)-y^2/(x^2-y^2) 的值。
▼优质解答
答案和解析
x/(x+y)+x/(x-y)-y^2/(x^2-y^2)
=1/[1+(x/y)]+1/[1-(x/y)]-1/[(x^2/y^2)-1]
=1/[1+5/3]+1/[1-5/3]-1/[(5/3)^2-1]
=1/(8/3)-1/(2/3)-1/[25/9-1]
=3/8-3/2-1/(16/9)=3/8-3/2-9/16
=(3*2-3*8-9)/16
=(6-24-9)/16
=-27/16