2022-2023年人教版数学八年级上册14.1.3《积的乘方》课时练习一、选择题1.计算(-2a2)3的结果是( )A.-6a2 B.-8a5 C.8a5 D.-8a62.计算(﹣3x2)3的结果是()A.9x5B.﹣9x5C.27x6D.﹣27x63.如果(ambn)3=a9b12,那么m,n的值等于()A.m=9,n=4B.m=3,n=4C.m=4,n=3D.m=9,n=64.下列计算正确的是( )A.(xy)3=x3yB.(2xy)3=6x3y3C.(-3x2)3=27x5D.(a2b)n=a2nbn5.如果(an•bmb)3=a9b15,那么( )A.m=4,n=3B.m=4,n=4C.m=3,n=4D.m=3,n=36.计算(-2a2)3的结果是( )A.-6a2 B.-8a5 C.8a5 D.-8a67.计算(﹣2a3)2的结果是( )A.2a5 B.4a5 C.﹣2a6 D.4a68.计算(ab2)3的结果是( )A.3ab2B.ab6 C.a3b5 D.a3b69.计算(﹣2a2b3)3的结果是( )A.﹣2a6b9B.﹣8a6b9C.8a6b9D.﹣6a6b910.计算﹣(﹣3a2b3)4的结果是( )A.81a8b12 B.12a6b7 C.﹣12a6b7 D.﹣81a8b1211.已知10x=3,10y=4,则102x+3y=( )A.574 B.575 C.576 D.57712.已知a=96,b=314,c=275,则a、b、c的大小关系是( )A.a>b>c B.a>c>b C.c>b>a D.b>c>a二、填空题13.计算:(3a)4=________;-(5a)2=________.
14.计算:(﹣2xy2)3= .15.若5m=3,5n=2,则52m+n= .16.计算:(﹣2xy3z2)2= .17.已知2x+3·3x+3=36x-2,则x的值为_______.18.若a+3b﹣2=0,则3a·27b=.三、解答题19.计算:(1)(2ab)3;(2)(-3x)4;(3)(xmyn)2;(4)(-3×102)4.20.计算:[(-3a2b3)3]2;21.计算:(-2xy2)6+(-3x2y4)3;22.已知n是正整数,且x3n=2,求(3x3n)3+(-2x2n)3的值.23.已知x3m=2,y2m=3,求(x2m)3+(ym)6-(x2y)3m·ym的值.
24.(1)若2x+5y-3=0,求4x•32y的值.(2)若26=a2=4b,求a+b值.25.已知2n=a,5n=b,20n=c,试探究a,b,c之间有什么关系.
参考答案1.D.2.D3.B4.D5.A6.D7.D8.D.9.B.10.D11.C12.C13.答案为:81a4,25a214.答案为:﹣8x3y6.15.答案为:18.16.答案为:4x2y6z4.17.答案为:7.18.答案为:9.19.解:(1)8a3b3. (2)81x4. (3)x2my2n. (4)8.1×109.20.解:原式=729a12b18.21.解:原式=37x6y12;22.解:(3x3n)3+(-2x2n)3=33×(x3n)3+(-2)3×(x3n)2=27×8+(-8)×4=184.23.解:原式=-5.24.解:(1)8;(2)11或-5;25.解:∵20n=(22×5)n=22n×5n=(2n)2×5n=a2b,且20n=c,∴c=a2b.