1-(a-(1-a)分之一)的平方÷(a的平方-2a+1)分之(a方-a+1)

问题描述:

1-(a-(1-a)分之一)的平方÷(a的平方-2a+1)分之(a方-a+1)

1-[a-1/(1-a)]²÷ (a²-a+1)/(a²-2a+1)
=1-[(a²-a+1)/(a-1)]²÷[(a²-a+1)/(a-1)²]
=1-(a²-a+1)²/(a-1)²×(a-1)²/(a²-a+1)
=1-(a²-a+1)
=-a²+a