先化简,在求值:x2-2x+1 1 -----------+---------- ,其中x=-1 X2-1 X+1_数学解答

先化简,在求值:x2-2x+1 1 -----------+---------- ,其中x=-1 X2-1 X+1

人气：451 ℃　时间：2020-06-12 14:41:54

解答

原式=1/(x-1)²+(x+1)/(x+1)(x-1)
=1/(x-1)²+1/(x-1)
=(1+x-1)/(x-1)²
=x/(x-1)²
=-1/(-1-1)²
=-1/4