已知x+y=-2,xy=-8,求y+1/x+1+x+1/y+1的值

x+y=-2,xy=-8,
y+1=-1-x
x+1=-1-y
y+1/x+1+x+1/y+1=(-1-x)/(x+1)+(-1-y)/(y+1)=-1-1=-2

答案: -2
你是求: (y+1)/(x+1)+(x+1)/(y+1) 吧

先通分
分母化成: (x+1)^2+(y+1)^2
y^2+2y+1+x^2+2x+1
(x+y)^2-2xy+(x+y)+2
分子化成:(x+1)(y+1)
x+y+xy+1
代入条件就是了

你好.我来帮你解答
根据X+Y=-2得X=-2-Y,所以X+1=-1-Y
到了这里想必你已经发现了吧,X+1与Y+1正好为相反数,所以Y+1/X+1=-1.X+1`/Y+1=-1
所以两式相加得-2

1/4
将1/x+1/y通分代数得1/4.然后x+y-2=0
所以最后结果1/4

天.你米加括号……555