两边乘a
a³-2a²+1=0
a³-a²-a²+1=0
a²(a-1)-(a²-1)=0
a²(a-1)-(a+1)(a-1)=0
(a-1)(a²-a-1)=0
a-1=0,a²-a-1=0
所以a=1,a=(1-√5)/2,a=(1+√5)/2
2a-a^2=1/a
2a^2-a^3=1
a^3-2a^2+1=0
a^3-a^2-(a^2-1)=0
a^2(a-1)-(a+1)(a-1)=0
(a-1)(a^2-a-1)=0
a-1=0,a^2-a-1=0
a=1,a=(1±√5)/2
经检验,a=1,a=(1±√5)/2是原方程的根