Question

初三数学先化简。再求值。a-1分之a+1-a的二次方-2a+1分之a除以a分之1。其中a=1-根号下2

清楚。速度

Answer 1

原式=(a+1)/(a-1)-[a/(1/a)]/(a�0�5-2a+1)
=(a+1)/(a-1)-a�0�5/(a-1)�0�5
=[(a+1)(a-1)-a�0�5]/(a-1)�0�5
=(a�0�5-1-a�0�5)/(a-1)�0�5
=-1/(a-1)�0�5
a=-1-√2
原式=-1/(-1-√2-1)�0�5=-1/(6+4√2)
=(2√2-3)/2=√2-3/2