若三次根号5x+2与三次根号5y+8互为相反数,则x+y=

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若三次根号5x+2与三次根号5y+8互为相反数,则x+y=

若三次根号5x+2与三次根号5y+8互为相反数,则x+y=
若三次根号5x+2与三次根号5y+8互为相反数,则x+y=

若三次根号5x+2与三次根号5y+8互为相反数,则x+y=
根据题意,三次方不改变符号,肯定 5x+2与5y+8 符号相反 ,
5x+2 = -(5y+8)
x+y = -2

5x+2+5y+8=0
x+y=-2

三次根号5x+2与三次根号5y+8互为相反数
则三次根号(5x+2)+三次根号(5y+8)=0
则三次根号(5x+2)=-三次根号(5y+8)
两边立方得:
(5x+2)=-(5y+8)
所以x+y=-2