计算:(1)(-x)3•(-x)•(-x)5(2)-3x•(4x2-13x+2)(3)(x4+2x3-12x2)÷(-12x)2(4)(a+2)(a-2)-(a-2)2(5)先化简,再求值:(a+1)

题目简介

计算:(1)(-x)3•(-x)•(-x)5(2)-3x•(4x2-13x+2)(3)(x4+2x3-12x2)÷(-12x)2(4)(a+2)(a-2)-(a-2)2(5)先化简,再求值:(a+1)

题目详情

计算:
(1)(-x)3•(-x)•(-x)5
(2)-3x•(4x2-
1
3
x+2)

(3)(x4+2x3-
1
2
x2÷(-
1
2
x)2

(4)(a+2)(a-2)-(a-2)2
(5)先化简,再求值:(a+1)2-a(a+3),其中a=2.
(6)先化简,再求值:(a+b)(a-b)+(a+b)2-2a2,其中a=3,b=-
1
3
题型:解答题难度:中档来源:不详

答案

(1)原式=(-x)9=-x9;
(2)原式=-12x3+x2-6x;
(3)原式=(x4+2x3-class="stub"1
2
x2)÷class="stub"1
4
x2=4x2+8x-2;
(4)原式=a2-4-a2+4a+4=4a;
(5)原式=a2+2a+1-a2-3a=-a+1,
当a=2时,原式=-2+1=-1;
(6)原式=a2-b2+a2+2ab+b2-2a2=2ab,
当a=3,b=-class="stub"1
3
时,原式=-2.

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