50题(有答案)
1.积的乘方法则用字母表示就是:当n为正整数时,(ab)n=_______. 2.在括号内填写计算所用法则的名称. (-x3yz2)2
=(-1)2(x3)2y2(z2)2( ) =x6y2z4 ( ) 3.计算:
(1)(ab2)3=________; (2)(3cd)2=________; (3)(-2b2)3=________; (4)(-2b)4=________; (5)-(3a2b)2=_______; (6)(-
323
ab)=_______; 2 (7)[(a-b)2] 3=______; (8)[-2(a+b)] 2=________. 专项练习: (1)(-5ab)
432
(3)(1ab2c3)3 (4)(0.2xy)
2
(2)-(3xy)
22
13
(5)(-1.1xy)
m3m2
(6)(-0.25)×4
1111
(7)(-a)·(-2a)
2232
(8)(-ab)-(-ab)
362243
- 1 -
(9)-(-xy)·(xy)
m3n+12
(10)2(ab)2+(ab)
nn22n
(11)(-22)+8(x)·(-x)·(-y)
(12)(-2×103)3
(13)(x2)n·xmn
(14)a2·(-a)2·(-2a2)3
(15)(-2a4)3+a6·a6
(16)(2xy2)2-(-3xy2)2
-
xy32223
(17)0.256(32)2
(18)(x4)2(x2)4x(x2)2x3(x)3(x2)2(x);
- 2 -
(19)(-
13nm-12a b)(4a3nb)2 4
(20)(-2a2b)3+8(a2)2·(-a)2·(-b)3
(21) 22m1168m1(4m)8m (m为正整数)
(22)(-3a2)3·a3+(-4a)2·a7-(5a3)3
(23)3ab(ab)
222
(24)(a)(a)
- 3 -
3223(25) [(-
23)8×(3872)]
(26)8
1999·(0.125)
2000
(27)(2a2b)3(12ab2)2
(28) (3a3)2a3(5a3)3
(29)[(2x2)3]2
(30) (18)9(8)9
- 4 -
(31)(520093)(2)2010 135
(32)(2102)2(3103)3.
(33)a4(3a3)2(4a5)2
(34)(ab)(ab)
423232
(35)(2
1111120321
1)10•(109821)10. )·(). (1098237
(37)已知2a3,3a4,求6a.
- 5 -
(38)(a3ax)ya20,当x2时,求y的值.
(39)化简求值:(-3a
2b)-8(a
32)
2·(-b)
2·(-a
2b),其中a=1,b=-1.
(40)先完成以下填空:
(1)26×56=( )6=10( ) (2)410×2510=( )10=10( ) 你能借鉴以上方法计算下列各题吗?
(3)(-8)10×0.12510
(4)0.252007×42006
(5)(-9)5·(-
2515
)·()33 (41)已知xn=2,yn=3,求(x2y)2n的值.
(42)一个立方体棱长为2×103厘米,求它的表面积(结果用科学记数法表示).
- 6 -
(43)已知2m=3,2n=22,则22m+n的值是多少
(44)已知9a23314,求a的值 38
(45).已知105,106,求1023的值
n(46)已知:x5,y3,求(xy)的值.
n2n
(47)已知x=5,y=3,求 (xy)-x
nn2
n2n的值。
(48)若有理数a,b,c满足(a-1)+|c+1|+|
2
b3n+13n+24n+2
|=0,试求ab- c 2- 7 -
(49)比较大小:218×310与210×318
(50)观察下列等式: 13=12; 13+23=32; 13+23+33=62; 13+23+33+43=102;
(1)请你写出第5个式子:______________ (2)请你写出第10个式子:_____________ (3)你能用字母表示所发现的规律吗?试一试!
- 8 -
答案: 知识点:
1.anbn 2.积的乘方法则,幂的乘方法则 3.(1)a3b6 (2)9c2d2 (3)-8b6 (4)16b4 • (5)-9a4b2 (6)-
278a6b3
专项练习:
(1)
25a2b2
(3)-6436927abc
(5)1.21x
2my
6m
(7)4a10
(9) x
3m2y
2n5
(11)7x6y3 (13)xm+n (15)-7a12 (17)14 (19)a124nb2m (21)0 (23)-2a2b2 (25) 1 (27) -2a8b7 (29) 64x12 7)(a-b)6 (8)4(a+b)2 (
2) -9x4y4
(4)125x8y6
( 6)-1
(
8)2a6b12 (10)3a
2nb
2n
12) -8×109 (14) -8a10 (16)-5x2y4
18)0
(20)-16a16b3 22)-136a9
24)0 26)0.125
28) 4a9 (30) 1
- 9 -
(
( ( ( ( ( ( (31)
13 (32)1.08×1013 5(33)-7a10 (34)a16b12
(35)
3 (36)1 7a(37)6=(2×3)a=2a×3a=3×4=12
(38)
3y+xy=20 当x=2时,3y+2y=20 Y=4 (39)
原式=-19ab=19 (40)
(1)2×5,6 (2)4×25,20 (3)1 (4)0.25 (5)32 (41) (x2y)2n =x
4n63y
22n=(x)(y)=2×3=144
n4n242(42)6×(2×103 )=2.4×107厘米2 (43) 2
2m+n
=(2)
22m
22n =36
3 (44)左边=(3a)(
18661816)=3a()=a 33916a=4 96 a=36 ( a)=36 a=6或-6
(45)1023=(10)(10)=5×6=5400 (46)提示:(xy)2n=[(xy)n]2=(xn·yn)2= (5×4)2=400.
- 10 -
a2b323332(47) (xy)n-x2n=x2nyn-x2n=52×3-52=50
2
(48)由题意知:a=1 b=0 c=-1 a3n+1b3n+2- c4n+2
=1
3n+1
×0
3n+2
-(-1)
4n+2
= -1
(49) 因为: 218×310=(2×3)10×28 210
×318=(2×3)10×38 所以: 218
×310
<210
×318
(50)(1)13+23+33+43+53=152 (2)13+23+•…+103=552 (3)13+23+……+n3=[n(n1)2
2]
- 11 -
因篇幅问题不能全部显示,请点此查看更多更全内容