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七(下)数学第八章幂的运算评估测试卷(时间:90分钟满分:100分)一、选择题(每小题2分,共50分)1.下列计算不正确的是()A.30+2-1=112B.10-4÷10-2=0.01C.a2n÷an=a2D.33132
8baba2.下列计算不正确的是()A.am÷am=a0=1B.am÷(an÷ap)=am-n-pC.(-x)5÷(-x)4=-xD.9-3÷(3-3)2=l3.下列计算正确的是()A.x8
÷x4=x2B.a8÷a-8=1C.3100÷399=3D.510÷55÷5-2=534.100m÷1000n的计算结果是()A.100000m-nB.102m-3nC.100mnD.1000mn5.若1
x=2,则x2+x-2的值是()A.4B.144C.0D.146.在等式am+n÷A=am-2中A的值应是()A.am+n+2B.an-2C.am+n+3D.an+27.a2m+4等于()A.2am+2B.(am)2a4C.a2·am+4D
.a2am+a48.xm+1xm-1÷(xm)2的结果是()A.-lB.1C.0D.±19.下列等式正确的是()①0.000126=1.26×10-4②3.10×104=31000③1.1×10-5=0.000011④12600000=1.
26×106A.①②B.②④C.①②③D.①③④10.(-23×103)2×(1.5×104)2的值是()A.-1.5×1011B.1014C.-4×1014D.-101411.下列各式中-定正确的是()A.(2x-3)0=1B.0=0C.(a2
-1)0=1D.(m2+1)0=112.计算200820091122的结果是()A.2009112B.200912C.200812D.200912
13.若26m>2x>23m,m为正整数,则x的值是()A.4mB.3mC.3D.2m14.在算式am+n÷()=am-2中括号内的式子应是()A.am+n+2B.an-2C.am+n-2D.
an+215.(2×3-12÷2)0结果为()A.0B.1C.12D.无意义16.结果为a2的式子是()A.a6÷a3B.a4a-2C.(a-1)2D.a4-a217.下面计算正确的是()A.a4a2=a8B.b3+b3=b6C.x5+x2=x7D.xx7=x818.(-2a
3)2等于()A.4a5B.4a6C.4a9D.-4a619.下列运算正确的是()A.x5x=x5B.x5-x2=x3C.(-y)2(-y)7=y9D.-y3·(-y)7=y1020.下列运算正确的是()A.x10÷(x4÷x2)=x8B.(xy)6÷(xy)2=(x
y)3=x3y3C.xn+2÷xn+1=x-nD.x4n÷x2nx3n=x-n21.计算25m÷5m得()A.5B.20C.5mD.20m22.1纳米=0.000000001米,则2.5纳米应表示为()A.2.5×10-8米B.2.5×10-9米C.2.5
×10-10米D.2.5×109米23.国家游泳中心——“水立方”是北京2008奥运会场馆之一,它的外层膜的展开面积约260000平方米,将260000用科学记数法表示应为()A.0.26×106B.26×104C.2.6×105D.2.6×10624.下列运算正确的是()A.a2a3=
a6B.(-y2)3=y6C.(m2n)3=m5n3D.-2x2+5x2=3x225.国家教育部最近提供的数据娃示,2008年全国普通高考计划招生667万人,这一数据科学记数法表示为(结果保留两个有效数字)()A.6.6×106B
.66×106C.6.7×106D.67×106二、填空题(每小题2分,共44分)26.a2·(-a)2=____________.27.(x2)-3·(x3)-1÷x=____________.28.-b2·(-b)2(-b3)=____
_________.29.(x-y)2(y-x)3=______________.30.0.1252008×82009=_____________.31.-4n÷8n-1=_____________.32.a3__________am+1=a2m+433
.已知10a=5,10b=25,则103a-b=____________.34.已知Axn+1=x2n+1,则A=_____________.35.0.258×643×258×48=______________.36.-
52×(-5)2×5-4=_____________.37.(a2)2(ab)3-(-a2b)3(-a)=______________.38.(-a)6÷(-a)3=____________.39.a2a5÷a6=___________
_.40.50×5-2+25-1=____________.41.m3·(m2)6÷m10=___________.42.-xm+1÷xm-1=___________.43.(am-1)n÷amn=___________.44.若22n=4,则n=__________.45.若64×83=2
x,则x=___________.46.若x3=(-2)5÷(12)-2,则x=____________.47.用科学记数法表示0.000000125=____________.三、计算题(48~51题每小题4分,52、53题每小题5分,
共26分)48.(-3a3)2÷a249.xn+1÷xn-1(xn)2(x≠0)50.x5x4-x6·x2·x51.(-3)0+(-12)3-(13)-252.3x2·xn-2+3(-x)2·xn-3·(-x)53.(
-3×3-2)-3-(-32)2÷32×20090参考答案1.C2.B3.C4.B5.B6.D7.B8.B9.C10.B11.D12.D13.A14.D15.D16.B17.D18.B19.D20.A21.C22.B23.C2
4.D25.C26.a427.101x28.b729.(y-x)530.831.-23-n32.am33.534.xn35.436.-137.038.-a339.a40.141.m542.-x243.1n
a44.145.1546.-247.1.25×10-748.解:(-3a3)2÷a2=9a6÷a2=9a6-2=9a449.解:xn+1·xn-1÷(xn)2=x(n+1)+(n-1)-2n=x0=150.解:x5·x4-x6
x2x=x9-x29=0.51.解:32011113198238852.解:原式=3xn-3xn=0.53.解:(-3×3-2)-3-(-32)2÷32×20090=-27-9
×1=-36