计算(1)172-152;(2)31927-1;(3)(-2a2b)2•(-ab)•(-12b2);(4)(2a2)•(3ab2-5ab3)(5)(-a2)3+a2•a4+a8÷(-a2);(6)2(

题目简介

计算(1)172-152;(2)31927-1;(3)(-2a2b)2•(-ab)•(-12b2);(4)(2a2)•(3ab2-5ab3)(5)(-a2)3+a2•a4+a8÷(-a2);(6)2(

题目详情

计算
(1)
172-152

(2)
3
19
27
-1

(3)(-2a2b)2•(-ab)•(-
1
2
b2)

(4)(2a2)•(3ab2-5ab3
(5)(-a23+a2•a4+a8÷(-a2);
(6)2(a-b)2-2(a-b)(a+b);
(7)(x+2y-3)(x-2y+3);
(8)求x的值:2(x+2)2-
72
49
=0
题型:解答题难度:中档来源:不详

答案

(1)原式=
(17+15)(17-15)
=
32×2
=
64
=8;
(2)原式=
3-class="stub"8
27
=-class="stub"2
3

(3)原式=4a4b2•ab•class="stub"1
2
b2=2a5b5;
(4)原式=6a3b2-10a3b3;
(5)原式=-a6+a6-a6=-a6;
(6)原式=2(a2-2ab+b2)-2a2+2b2=2a2+4ab+2b2-2a2+2b2=4ab+4b2;
(7)原式=[x+(2y-3)][x-(2y-3)]=x2-(2y-3)2=x2-4y2+12y-9;
(8)∵2(x+2)2-class="stub"72
49
=0,
∴(x+2)2=class="stub"36
49

∴x+2=±class="stub"6
7

即x1=-class="stub"8
7
,x2=-class="stub"20
7

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