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春芽
共回答了20个问题采纳率:100% 举报
(x³+x+1)/x³
=1+1/x²+1/x³
=1+(1/x)²+(1/x)³
=1+4/(√5+1)²+8/(√5+1)³
=1+4(√5+1)/(√5+1)³+8/(√5+1)³
=1+[4(√5+1)+8]/(√5+1)³
=1+[4√5+12]/(√5+1)³
=1+2(6+2√5)/(√5+1)³
=1+2(√5+1)²/ (√5+1)³
=1+2/(√5+1)
=1+2(√5-1)/(√5+1)(√5-1)
=(1+√5)/2
1年前
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