a-1分之a的平方-a-1
=(a²-a-1)/(a-1)
=(a²-2a+1+a-2)/(a-1)
=[(a-1)²+(a-1)-1]/(a-1)
=a-1+1-[1/(a-1)]
=a-[1/(a-1)]
计算:a-1分之a的平方-a-1
a-1分之a的平方-a-1
=(a²-a-1)/(a-1)
=(a²-2a+1+a-2)/(a-1)
=[(a-1)²+(a-1)-1]/(a-1)
=a-1+1-[1/(a-1)]
=a-[1/(a-1)]