先化简,再求值:(
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原式=[
-x2+x x-1
]÷(x+1)(x-1) x-1 x2(x+1) (x-1)2
=
•x2+x-x2+1 x-1 (x-1)2 x2(x+1)
=
•x+1 x-1 (x-1)2 x2(x+1)
=
,x-1 x2
解不等式
,x>-1① 3(x+1)≤x+7②
由①得,x>-1;
由②得,x≤2;
则不等式的解集为-1<x≤2,
其整数解为0,1,2;
当x=0或x=1时,使得原式及解答过程中的分式分母为0,故x=2;
当x=2时,原式=
=2-1 22
.1 4