(1)计算|1-3|+3×3-1+2sin60°-9;(2)化简x(x+2x3y)-(x+1)2+2x;(3)先化简,再求值aa+2-8a2-4÷4a-2,其中a=-3.-数学

题目简介

(1)计算|1-3|+3×3-1+2sin60°-9;(2)化简x(x+2x3y)-(x+1)2+2x;(3)先化简,再求值aa+2-8a2-4÷4a-2,其中a=-3.-数学

题目详情

(1)计算|1-
3
|+3×3-1+2sin60°-
9

(2)化简x(x+2x3y)-(x+1)2+2x;
(3)先化简,再求值
a
a+2
-
8
a2-4
÷
4
a-2
,其中a=-3.
题型:解答题难度:中档来源:雅安

答案

(1)|1-
3
|+3×3-1+2sin60°-
9

=
3
-1+1+
3
-3,
=2
3
-3;

(2)原式=x2+2x4y-x2-2x-1+2x,
=2x4y-1;

(3)原式=class="stub"a
a+2
-class="stub"8
(a+2)(a-2)
×class="stub"a-2
4

=class="stub"a
a+2
-class="stub"2
a+2

=class="stub"a-2
a+2

当a=-3时,原式=5.

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