湘教版數(shù)學(xué)八年級(jí)上冊(cè)1.3.1　同底數(shù)冪的除法同步課時(shí)練習(xí)（word版含答案）

1、1.3.1同底數(shù)冪的除法知識(shí)點(diǎn) 1同底數(shù)冪的除法法則1.計(jì)算a10a2的結(jié)果是()A.a5B.a-5C.a8D.a-82.計(jì)算(-x)12x3的結(jié)果是()A.-x4B.x4C.-x9D.x93.下列計(jì)算中正確的是()A.a2a2=0B.a2a=1C.a6a3=a2D.a5a=a44.若xmx3n=x,則m與n的關(guān)系是()A.m=3nB.m=-3nC.m-3n=-1D.m-3n=15.計(jì)算:(ab)7(ab)3=,3a4b5cab2=.6.計(jì)算:(1)(-a)8(-a)4;(2)-a4na4n;(3)(x-y)6(x-y)3(y-x)2.知識(shí)點(diǎn) 2同底數(shù)冪的除法法則的逆用7.若3m=5,3n=4

2、,則3m-n的值為()A.54B.3C.21D.208.已知am=3,an=2,則a2m-n的值為.9.計(jì)算(a3)3(-a2)4的結(jié)果是()A.a4B.a3C.a2D.a10.已知一個(gè)長(zhǎng)方體的體積為(a-2b)3,它的底面積為(a-2b)2,則這個(gè)長(zhǎng)方體的高為()A.a+2bB.a-2bC.(a+2b)2D.(a-2b)211.計(jì)算:(1)(-2x3)2(-x2)(-x)23;(2)(-3x2n+2yn)3(-x3y)2n.12.已知an=2,am=3,ak=4,試求a2n+m-2k的值.13.若(xmx2n)3xm-n與4x2為同類項(xiàng),且2m+5n=7,求4m2-25n2的值.答案1.C

3、a10a2=a10-2=a8.故選C.2.D3.D4.D 因?yàn)閤mx3n=xm-3n=x,所以m-3n=1.故選D.5.a4b43a3b3c (ab)7(ab)3=(ab)7-3=(ab)4=a4b4,3a4b5cab2=3a4-1b5-2c=3a3b3c.6.解:(1)原式=(-a)8-4=(-a)4=a4.(2)原式=-a4na4n=-1.(3)原式=(x-y)6(x-y)3(x-y)2=(x-y=x-y.7.A8.92 因?yàn)閍m=3,所以a2m=32=9,所以a2m-n=a2man=92.9.D 原式=a9a8=a.10.B 長(zhǎng)方體的高=(a-2b)3(a-2b)2=a-2b.11.解:(1)原式=4x6(-x2)(-x)6=-4x8x6=-4x2.(2)原式=-27x6n+6y3n(-x3y)2n=-27x6n+6y3nx6ny2n=-27x6yn.12.解:因?yàn)閍n=2,am=3,ak=4,所以a2n+m-2k=a2nama2k=(an)2am(ak)2=4316=34.13.解:(xmx2n)3xm-n=(xm-2n)3xm-n=x3m-6nxm-n=x2m-5n.因?yàn)?xmx2n)3xm-n與4x2為同類項(xiàng),所以2m