证明5的60次方减1是56的倍数
证明5的60次方减1是56的倍数
5^60-1 =(5^30+1)(5^30-1) =(5^30+1)(5^15+1)(5^15-1) =(5^30+1)(5^15+1)(25^3-1) =(5^30+1)(5^15+1)[(25-1)(25^2+25*1+1)] =(5^30+1)(5^15+1)[24*651] =(5^30+1)(5^15+1)[(3*8)(7*93)] =(5^30+1)(5^15+1)(56*3*93) 嗯,答案就出来了吧
5^60-1=(5^30+1)(5^30-1)=(5^30+1)(5^15+1)(5^15-1)=(5^30+1)(5^5+1)*a*(5^5-1)*b=(5^30+1)a*b*(5^10-1)=。。。。这样用二次,三次拆分,到后面就知道了
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