a²-3a+1=0等式两边同除以aa-3+1/a=0a+1/a=3a³+1/a³=(a+1/a)(a²-1+1/a²=(a+1/a)[(a+1/a)²-3]=3(9-3)=18a^8+1/a^8=(a^4+1/a^4)²-2=[(a²+1/a)²-2]²-2={[(a+1/a)...