先化简,再求值：x²-1分之x平方-x-2 ÷x分之2x-4

先化简,再求值：x²-1分之x平方-x-2 ÷x分之2x-4
先化简,再求值：x²-1分之x平方-x-2 ÷x分之2x-4

先化简,再求值：x²-1分之x平方-x-2 ÷x分之2x-4
[(x²-x-2)/(x²-1)]÷[(2x-4)/x]
=[(x-2)(x+1)]/[(x+1)(x-1)]×[x/[2(x-2)]
=[(x-2)/(x-1)]×[x/[2(x-2)]
=x/[2(x-1)]
……往下将x至代入即可.

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