- tt白
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x+y=-4
平方
x²+y²+2xy=16
x²+y²=16-2xy=16+24=40
原式通分=[(y+1)²+(x+1)²]/(x+1)(y+1)
=(x²+2x+1+y²+2y+1)/(xy+x+y+1)
=[(x²+y²)+2(x+y)+2]/[xy+(x+y)+1]
=(40-8+2)/(-12-4+1)
=-34/15
- 豆豆staR
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(x+1)(y+1)=xy+x+y+1=-15
(x+y)^2=x^2+2xy+y^2
x^2+y^2=(x+y)^2-2xy=(-4)^2-2xy=40
(y+1)/(x+1)+(x+1)/(y+1)
=((x+1)^2+(y+1)^2)/((x+1)(y+1))
=(x^2+2x+1+y^2+2y+1)/((x+1)(y+1))
=(x^2+y^2+2(x+y)+2)/((x+1)(y+1))
=(40+2*(-4)+2)/(-15)
=-34/15
- 苏州马小云
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原式=((y+1)^2+(x+1)^2)/((x+1)(y+10))
=((x+y)^2-2xy+2(x+y)+1)/(xy+x+y+1)
再带入求解
应该是这样的
- 皮皮
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通分化简即可,但是题目有问题,据提议(x+y)²=16,xy=12 x²+y²=-8,两个数的平方怎么可能等于负数。题目有问题吧