8.2 幂的乘方与积的乘方(1)
1.下列计算正确的是 ( )
A.x3.x2=2x6 B.x4.x2=x8 C.(-x2)3=-x6 D.(x3)2=x5
2.下列运算正确的是 ( )
A.x3.x2=x5 B.(x3)3=x6 C.x5+x5=x10 D.x6-x3=x3
3.(1)① =_______,②(a5)6=_______,③[(-8)3]2=_______;
(2)①(x3)2n=_______,②(a2)n.a3=_______,③(a2)4.(-a)3=_______;
(3)①x12=( )6=( )4=( )3=( )2,②(a2)( ).a3=a11.
4.(1)若 ax=2,则 a3x=_______;
(2)若 a、b 为正整数,且 3a.9b=81,则 a+2b=_______.
5.已知:2+ =22× ,3+ =32× ,4+ =42× ……若 10+ =102× (a、b
为正整数),则 a+b=_______.
6.计算:
(1)(103)5 (2)[(-a)3]2 (3)[(x2)3]7;
(4)(-a3)2.(-a2)3; (5)(a2)n.(a3)2n; (6)27a·3b;
(7)(x2)n-(xn)2; (8)a2.a4+(-a2)3; (9)(a2)3-a3.a3+2(a3)2.
7.下列运算正确的是 ( )
A.-a4.a3=a7 B.a4.a3=a12 C.(a4)3=a12 D.a4+a3=a7
8.(-ak-1)2 等于 ( )
A.-a2k-1 B.a2k-2 C.a2k-2 D.2ak-1
9.若 3×9m×27m=311,则 m 的值为 ( )
A.2 B.3 C.4 D.5
10.(1)(x4)3=_______,(-y2)3=_______,(am)2=_______;
(2)x30=(_______)6=(x3._______)2=[x.(-x3).(_______)3]3.
421
3
2
3
2
3
3
8
3
8
4
15
4
15
a
b
a
b11.(1)若 2a+3b=-2,,则 9a.27b 的值为_______;
(2)已知 4x=2x+3,则 x=_______.
12.计算:
(1)(-a2)3.(-a3)4; (2)a4.a4+(-a2)4-3(a4)2;
(3) (-a2)3.a3+4(-a)2.a7-5(a3)3; (4)a5 . a7 + ( - a4)3 - 2a2 . (a2)5 +
3[(a3)3.a3]
13.求值:
(1)若 xm.x2m=-2,求 x9m 的值; (2)已知 am=-2,an=3,求 a3m+2n 的值.
14.(1)已知 m 为正整数,且 4×8m×16m=48,求 m 的值;
(2)已知:x=3m-2,y=5+9m,用含 x 的代数式表示 y.参考答案
1.C 2.A 3.(1)① ②a30 ③86 (2)①x6n ②a2n+3 ③-a11 (3)①x2,x3,x4,x6
② 4 4.(1)8 (2)4 5.109 6.(1)1015 (2)a6 (3)x42 (4)-a12 (5)a8n
(6)33a+b (7)0 (8)0 (9)2a6
7.C 8.C 9.A 10.(1)x12-y6 a2m (2)x5 x12 -x2 11.(1)3-2
(2)3 12.(1)-a18 (2)-a8 (3)-2a9 (4)a12 13.(1)-8 (2)-72 14.(1)2 (2)y
=5+(x+2)2
幂的乘方与积的乘方(2)
1.计算(ab)2 的结果是 ( )
A.2ab B.a2b C.a2b2 D.ab2
2.下列计算正确的是 ( )
A.a3.a2=a6 B.a2+a4=2a2 C.(a3)2=a6 D.(3a)2=a6
3.(1)①(-2x)3=_______,②(-4a2b3)4=_______,③(anbn+1)3=_______;
(2)①(3×102)3=_______,②-(-4×103)2=_______;
(3)①0.027x9y6=( )3,②-32a10b15=( )5,③a6nb18n=( )6n.
4.(1)( )100×(-3)100=_______; (2)(- )100×2101=_______.
5.若 xn=3,yn=-2,则(xy)n 的值是_______;(x2y3)n 的值是_______.
6.计算:
(1)[-3(-xn)]3; (2)(-1.5a3)2.(-4a)3;
(3)a5.(-a)3+(-2a2)4; (4)(0.125)2012×(-8)2011;
(5) (-2a)3-(-a).(3a)2; (6) (a2)3-3a3.a3+(-2a3)2.
1
2
81
3
1
37.计算(-2x2)3 的结果是 ( )
A.-2x5 B.-8x6 C.-2x6 D.-8x5
8.已知(ax.ay)5=a20 (a>0,且 a≠1),那么 x、y 应满足 ( )
A.x+y=15 B.x+y=4 C.xy=4 D.y=
9.计算(-2)100+(-2)99 所得的结果是 ( )
A.-2 B.2 C.-299 D.299
10.(-2x2y)3=_______;(-0.5mn2)3=_______;(-anbn-1)6=_______.
11.若(ambnb)3=a9b15,求 2m+n 的值是_______.
12.计算:
(1) ; (2) (-x4)3.(-x3)3;
(3)2(2a3)2.a3-(3a3)3+(5a)2.a7; (4) a3.a3.a2+(a4)2+(-2a2)4
(5) ; (6) .
13.若 x2n=5,求(3x3n)2-4(x2)2n 的值.
14.一个正方体的棱长为 5×103mm,求这个正方体的表面积和体积.
4
x
3
5 22
3
na b −
( ) ( )2012
2011 20112 1.5 13
− × × −
( ) ( )8 250.125 2× −参考答案
1.C 2.C 3.(1)①-8x3 ②256a8b12 ③a3nb3n+3 (2)①2.7×107
②-1.6×107 (3)①0.3x3y2 ②-2a2b3 ③ab3 4.(1)1 (2)2 5.-6 -72 6.(1)27x3n
(2)-144a9 (3)15a8 (4)-0.125 (5)a3 (6)2a6
7.B 8.B 9.D 10.-8x6y3 -0.125m3n6 a6nb6n-6 11.128
12.(1) (2)x21 (3)0 (4)18a8 (5)- (6)-2
13.1025 14.1.5×108mm2,1.25×1011 mm3
15 68
27
na b− 2
3