计算或化简(1)计算:(-1)2013-(3-2)0+(12)-1(2)化简:(x2x+4-16x+4)÷x-4x(3)化简:(1-1a-1)÷a2-4a+4a2-a(4)先化简(aa+2+2a-2)

题目简介

计算或化简(1)计算:(-1)2013-(3-2)0+(12)-1(2)化简:(x2x+4-16x+4)÷x-4x(3)化简:(1-1a-1)÷a2-4a+4a2-a(4)先化简(aa+2+2a-2)

题目详情

计算或化简
(1)计算:(-1)2013-(
3
-
2
)0+(
1
2
)-1

(2)化简:(
x2
x+4
-
16
x+4
x-4
x

(3)化简:(1-
1
a-1
a2-4a+4
a2-a

(4)先化简(
a
a+2
+
2
a-2
1
a2-4
,然后选取一个合适的整数a代入求值,其中-2≤a≤2.
题型:解答题难度:中档来源:不详

答案

(1)原式=-1-1+2
=0;

(2)原式=
(x+4)(x-4)
x+4
÷class="stub"x-4
x

=(x-4)×class="stub"x
x-4

=x;

(3)原式=class="stub"a-2
a-1
÷
(a-2)2
a(a-1)

=class="stub"a-2
a-1
×
a(a-1)
(a-2)2

=class="stub"a
a-2


(4)原式=
a(a-2)+2(a+2)
(a+2)(a-2)
×(a+2)(a-2)
=a(a-2)+2(a+2)
=a2-2a+2a+4
=a2+4,
当a=1时,原式=1+4=5.

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