化简(a-a+1分之a)÷a²-4分之a²-2a×a²+3a+2分之a-1

化简(a-a+1分之a)÷a²-4分之a²-2a×a²+3a+2分之a-1
化简(a-a+1分之a)÷a²-4分之a²-2a×a²+3a+2分之a-1

化简(a-a+1分之a)÷a²-4分之a²-2a×a²+3a+2分之a-1
=(a²+a-a)/(a+1)×(a+2)(a-2)/a(a-2)×(a-1)/(a+1)(a-1)
=a²/(a+1)×(a+2)/a×1/(a+1)
=a(a+2)/(a+1)²