=2a^4+a^3+2a^2+2a^2+a+2 2a^2(a^2+1)+a(a^2+1)+2(a^2+1)
_______________________ = ___________________________ =
2(a^3-1)-a(a-1) 2(a-1)(a^2+a+1)-a(a-1)
(2a^2+a+2)(a^2+1) (2a^2+a+2)(a^2+1) a^2+1
=________________ = _________________ = ______
(2a^2+2a+2-a)(a-1) (2a^2 +a+2)(a-1) a-1