匿名使用者
匿名使用者 發問時間: 科學數學 · 1 0 年前

我有個有關數學上的難題

請列明計算過程

7的40次方,個位數是甚麼,十位數又是什麼?

5 個解答

評分
  • 匿名使用者
    1 0 年前
    最佳解答

    個位數是1

    十位數是0

    7的1次方=7

    7的2次方=49

    7的3次方=343

    7的4次方=2401

    7的5次方=16807

    7的6次方=.....649

    7的7次方=........43

    最後你不需要乘到百位以上

    因為用不到

    你會發現

    他是四個一循環的

    這種題目一定是有規律

    他才會問

    參考資料: 自己
  • dd
    Lv 6
    1 0 年前

    72-1 ≡ 71 ≡ 1 (mod 2)75-1 ≡ 74 ≡ 1 (mod 5)74 ≡ 1 (mod 10)74-1 ≡ 0 (mod 10)(74-1)2 ≡ 0 (mod 100)78-2*74+1 ≡ 0 (mod 100)78 ≡ 2*74-1 (mod 100)78 ≡ 2*2401-1 ≡ 2*1-1 ≡ 1 (mod 100)740 ≡ (78)5 ≡ 15 ≡ 1 (mod 100)所以個位數=1十位數=0

  • 匿名使用者
    1 0 年前

    7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    49*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    343*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    2401*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    16807*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    117649*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    823543*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    5764801*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    40353607*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    282475249*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    1977326743*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    13841287201*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    96889010407*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    678223072849*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    4747561509943*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    33232930569601*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    232630513987207*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    1628413597910449*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    11398895185373143*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    79792266297612001*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    558545864083284007*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    3909821048582988049*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    27368747340080916343*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    191581231380566414401*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    1341068619663964900807*7*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    9387480337647754305649*7*7*7*7*7*7*7*7*7*7*7*7*7*7=

    65712362363534280139543*7*7*7*7*7*7*7*7*7*7*7*7*7=

    489986536544739960976801*7*7*7*7*7*7*7*7*7*7*7*7=

    3219905755813179726837607*7*7*7*7*7*7*7*7*7*7*7=

    22539340290692258087863249*7*7*7*7*7*7*7*7*7*7=

    157775382034845806615042743*7*7*7*7*7*7*7*7*7=

    1104427674243920646305299201*7*7*7*7*7*7*7*7=

    7730993719707444524137094407*7*7*7*7*7*7*7=

    54116956037952111668959660849*7*7*7*7*7*7=

    378818692265664781682717625943*7*7*7*7*7=

    265173084585965347177902381601*7*7*7*7=

    18562115921017574302453163671207*7*7*7=

    129934811447123020117172145698449*7*7=

    909543680129861140820205019889143*7=

    6366805760909027985741435139224001

    個位數為1

    十位數為0

    參考資料: 自己算
  • 1 0 年前

    7的1次方 個位數是7

    7的2次方 個位數是9

    7的3次方 個位數是3

    7的4次方 個位數是1

    7的5次方 個位數是7

    以此類推 7的40次方 個位數是1

  • 您覺得這個回答如何?您可以登入為回答投票。
  • 1 0 年前

    Anny說的對...

    順帶一提...如果看到有很高的次方時通常都是有規律ㄉ

還有問題?馬上發問,尋求解答。