已知x=根号5-2分之根号5-2,y=根号5+2分之根号5-2.求(1)x+y (2)xy (3)x+y分之x²+3xy+y²已知x=根号5-2分之根号5+2,y=根号5+2分之根号5-2.求(1)x+y (2)xy (3)x+y分之x²+3xy+y²。(2和-2都在根号外)
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已知x=根号5-2分之根号5-2,y=根号5+2分之根号5-2.求(1)x+y (2)xy (3)x+y分之x²+3xy+y²
已知x=根号5-2分之根号5+2,y=根号5+2分之根号5-2.求(1)x+y (2)xy (3)x+y分之x²+3xy+y²。(2和-2都在根号外)
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