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第二题求解谢谢
1个回答
展开全部
解:x^2-3x+1=0
x+1/x=3
x^2+1/x^2+2=9
x^2+1/x^2=7
x^3+1/x^3
=(x+1/x)(x^1+1/x^2-1)
=3*(7-1)
=3*6
=18
所以选A
x+1/x=3
x^2+1/x^2+2=9
x^2+1/x^2=7
x^3+1/x^3
=(x+1/x)(x^1+1/x^2-1)
=3*(7-1)
=3*6
=18
所以选A
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