已知x+y=[负4],xy=[负12],求分式[y+1/x+1]+[x+1/y+1]的值

问题描述:

已知x+y=[负4],xy=[负12],求分式[y+1/x+1]+[x+1/y+1]的值
1个回答 分类:数学 2014-11-12

问题解答:

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[y+1/x+1]+[x+1/y+1]
=(y+1)^2/(x+1)(y+1)+(x+1)^2/(x+1)(y+1)
=[(Y+1)^2+(x+1)^2]/(x+1)(y+1)
=[y^2+2y+1+x^2+2x+1]/[xy+x+y+i]
=[(y+x)^2-2xy+2x+2y+2]/[-12-4+1]
=[(-4)^2-2(-12)+2(-4)+2]/(-15)
=-510
 
 
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