楼上好像错了!原式=a^2+a^2-2a+1+a^2(a+1)^2 =a^2(a+1)^2-2a(a+1)+1 ---(2a^2)变成了-(2a^2) =[a(a+1)-1]^2 =(a^2+a-1)^2依我看此题无解.
原式=a^2+a^2-2a+1+a^2(a+1)^2 =a^2(a+1)^2-2a(a+1)+1 =[a(a+1)-1]^2 =(a^2+a-1)^2