20春華師《初等數(shù)論》在線作業(yè)

)1:6（A:1B:2C:3D:4正確答案:D(單選)2:(221,391,136)=( ).A:13B:17C:19D:23正確答案:B)3:6x≡18(mod3)解的個(gè)數(shù)為（A:1B:2C:3D:4個(gè)解正確答案:)4:下面的（）12A:0,1，5，11B:C:1，5，7，11D:1，-1，2，-2正確答案:C)5:5（A:-2,-1,0,1,2B:-5,-4,-3,-2,-1C:1,2,3,4,5D:0,1,2,3,4正確答案:D)6:525x+231y=210（A:有解B:無(wú)解C:解都是正數(shù)D:解都是負(fù)數(shù)正確答案:A)7:下列關(guān)于質(zhì)數(shù)、合數(shù)的說(shuō)法，正確的是（A:兩個(gè)質(zhì)數(shù)之和一定是質(zhì)數(shù)B:質(zhì)數(shù)一定是奇數(shù)C:兩個(gè)合數(shù)之和一定是合數(shù)D:兩個(gè)質(zhì)數(shù)之積一定是合數(shù)正確答案:D)8:如果b|a，a|c，則（A:b=cB:C:b|cD:c|b正確答案:C)9:下述結(jié)論正確的是（）A:若21x≡70(mod112)，則同余式必有14個(gè)解B:同余式5x≡13(mod43)有唯一解x≡37(mod43)C:同余式5x≡13(mod43)有唯一解x=37D:同余式3x≡9(mod15)無(wú)解正確答案:C)10:4（A:-2,-1,0,1B:-4,-3,-2,-1C:1,2,3,4D:0,1,2,3正確答案:D)11:下列說(shuō)法錯(cuò)誤的是（A:101B:素?cái)?shù)有無(wú)限多個(gè)C:奇數(shù)一定能表示為兩平方數(shù)之差D:兩個(gè)連續(xù)自然數(shù)互質(zhì)正確答案:A)12:1030（A:4B:5C:6D:7正確答案:C)13:1050858（A:2B:3C:6D:12正確答案:C(單選)14:下列各組數(shù)哪一組是模8的完全剩余系（ A:1,3,5,7,9,11,13,15B:2,4,6,8,17,21,23C:-7,-12,-17,-22,-27,-32,-37,-42D:–2,–7,11,15,18,21,24,27正確答案:C)15:1251018（）A:1B:2C:3D:4正確答案:C)16:1577（A:22B:23C:24D:25正確答案:D)17:如果nn(n+1)是（A:奇數(shù)B:偶數(shù)C:奇數(shù)或偶數(shù)D:由n正確答案:B)18:n01n23是（）A:1110B:1101C:1011D:1001正確答案:A)19:下列命題中不正確的是（）A:整數(shù)a1，a2，…，anB:整數(shù)a1，a2，…，anC:整數(shù)aD:整數(shù)a正確答案:D(單選)20:能被4,5,7整除的最小的正整數(shù)是（ ）.A:120B:130C:140D:150正確答案:C)21:3|n7|nA:錯(cuò)誤B:正確正確答案:B)22:294194A:錯(cuò)誤B:正確正確答案:B)23:111A:錯(cuò)誤B:正確正確答案:A)24:存在數(shù)m，使ψ(m)A:錯(cuò)誤B:正確正確答案:A)25:已知ψ(m)=4，則mA:錯(cuò)誤B:正確正確答案:B)26:歐拉函數(shù)ψ(480)A:錯(cuò)誤B:正確正確答案:B)27:若(a,b)=(a,c),則A:錯(cuò)誤B:正確正確答案:A)28:若(a,m)=1，x通過(guò)模m的簡(jiǎn)化剩余系，則ax+b也通過(guò)模mA:錯(cuò)誤B:正確正確答案:A)29:2009A:錯(cuò)誤B:正確正確答案:B)30:5A:錯(cuò)誤B:正確正確答案:A)1:6（A:1B:2C:3D:4正確答案:D(單選)2:(221,391,136)=( ).A:13B:17C:19D:23正確答案:B)3:6x≡18(mod3)解的個(gè)數(shù)為（A:1B:2C:3D:4確答案:)4:下面的（）12A:0,1，5，11B:C:1，5，7，11D:1，-1，2，-2正確答案:C)5:5（A:-2,-1,0,1,2B:-5,-4,-3,-2,-1C:1,2,3,4,5D:0,1,2,3,4正確答案:D)6:525x+231y=210（A:有解B:無(wú)解C:解都是正數(shù)D:解都是負(fù)數(shù)正確答案:A)7:下列關(guān)于質(zhì)數(shù)、合數(shù)的說(shuō)法，正確的是（A:兩個(gè)質(zhì)數(shù)之和一定是質(zhì)數(shù)B:質(zhì)數(shù)一定是奇數(shù)C:兩個(gè)合數(shù)之和一定是合數(shù)D:兩個(gè)質(zhì)數(shù)之積一定是合數(shù)正確答案:D)8:如果b|a，a|c，則（A:b=cB:C:b|cD:c|b正確答案:C)9:下述結(jié)論正確的是（）A:21x≡70(mod11214同余式5x≡13(mod43)有唯一解C:5x≡13(mod43)有唯一解x=37D:3x≡9(mod15正確答案:C)10:4（A:-2,-1,0,1B:-4,-3,-2,-1C:1,2,3,4D:0,1,2,3正確答案:D)11:下列說(shuō)法錯(cuò)誤的是（A:101B:素?cái)?shù)有無(wú)限多個(gè)C:奇數(shù)一定能表示為兩平方數(shù)之差D:兩個(gè)連續(xù)自然數(shù)互質(zhì)正確答案:A)12:1030（A:4B:5C:6D:7正確答案:C)13:1050858（A:2B:3C:6D:12正確答案:C(單選)14:下列各組數(shù)哪一組是模8的完全剩余系（ A:1,3,5,7,9,11,13,15B:2,4,6,8,17,21,23C:-7,-12,-17,-22,-27,-32,-37,-42D:–2,–7,11,15,18,21,24,27正確答案:C)15:1251018A:1B:2C:3D:4正確答案:C)16:1577（A:22B:23C:24D:25正確答案:D)17:如果nn(n+1)是（A:奇數(shù)B:偶數(shù)C:奇數(shù)或偶數(shù)D:由n正確答案:B

）種不同的付法)18:n01n23是（）A:1110B:1101C:1011D:1001正確答案:A)19:下列命題中不正確的是（）A:整數(shù)a1，a2，…，anB:整數(shù)a1，a2，…，anC:整數(shù)aD:整數(shù)a與它的絕對(duì)值有相同的約數(shù)正確答案:D(單選)20:能被4,5,7整除的最小的正整數(shù)是（ ）.A:120B:130C:140D:150正確答案:C)21:3|n7|nA:錯(cuò)誤B:正確正確答案:B)22:294194A:錯(cuò)誤B:正確正確答案:B)23:111A:錯(cuò)誤B:正確正確答案:A)24:存在數(shù)m，使ψ(m)A:錯(cuò)誤B:正確正確答案:A(判斷題)25:已知ψ(m)=4，則m可能為5.A:錯(cuò)誤B:正確正確答案:B)26:歐拉函數(shù)ψ(480)A:錯(cuò)誤B: