计算:①-4x4-4-12-x;②a2a-1-a-1;③(x+2x2-2-x-1x2-4x+4)•xx-4,其中x=1;④15×3520÷(-136);⑤45+1220-515.-数学

题目简介

计算:①-4x4-4-12-x;②a2a-1-a-1;③(x+2x2-2-x-1x2-4x+4)•xx-4,其中x=1;④15×3520÷(-136);⑤45+1220-515.-数学

题目详情

计算:
-4 
x4-4 
-
1
2-x

a2
a-1
-a-1;
(
x+2
x2-2
-
x-1
x2-4x+4
)
x
x-4
,其中x=1;
15
×
3
5
20
÷(-
1
3
6
)

45
+
1
2
20
-5
1
5
题型:解答题难度:中档来源:不详

答案

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

②原式=
a2
a-1
-
(a+1)(a-1)
a-1
=
a2-(a2-1)
a-1
=class="stub"1
a-1

③当x=1时,原式=(class="stub"3
-1
-0)•class="stub"1
-3
=1;
④原式=-
15
×
6
5
5
class="stub"3
6
=-
9
10
5

⑤原式=3
5
+
5
-
5
=3
5

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