计算与解方程(1)(x+2x2-2x-x-1x2-4x+4)÷x-4x(2)x+1x-1-4x2-1=1.-数学

题目简介

计算与解方程(1)(x+2x2-2x-x-1x2-4x+4)÷x-4x(2)x+1x-1-4x2-1=1.-数学

题目详情

计算与解方程
(1)(
x+2
x2-2x
-
x-1
x2-4x+4
x-4
x

(2)
x+1
x-1
-
4
x2-1
=1
题型:解答题难度:中档来源:不详

答案

(1)原式=[class="stub"x+2
x(x-2)
-class="stub"x-1
(x-2)2
]•class="stub"x
x-4

=
(x+2)(x-2)-x(x-1)
x(x-2)2
class="stub"x
x-4

=class="stub"-3x
x(x-2)2
class="stub"x
x-4

=class="stub"-3x
(x-2)2(x-4)


(2)方程两边同时乘以(x+1)(x-1),得:(x+1)2-4=x2-1,
即x2+2x+1-4=x2-1,
则2x-3=-1,
解得:x=1,
检验:当x=1时,(x+1)(x-1)=0,则x=1不是方程的解.
方程无解.

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