1.(2+5+8+...+2000)-1+4+7+...1999 (2000-2)/3+1-1=666解法一;(2+1999)+(5+1996)+.+(1997+4)+(2000-1)=2001+2001+.+2001+1999=2001*666+1999=1332666+1999=1334665解法二;(2-1)+(5+4)+(8+7)+.(2000+1999) (3999-9)/3+1=666=1+(9+15+21+.+3999)=1+(3999+9)*666/2
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/11 22:50:12
![1.(2+5+8+...+2000)-1+4+7+...1999 (2000-2)/3+1-1=666解法一;(2+1999)+(5+1996)+.+(1997+4)+(2000-1)=2001+2001+.+2001+1999=2001*666+1999=1332666+1999=1334665解法二;(2-1)+(5+4)+(8+7)+.(2000+1999) (3999-9)/3+1=666=1+(9+15+21+.+3999)=1+(3999+9)*666/2](/uploads/image/z/15005989-37-9.jpg?t=1.%EF%BC%882%2B5%2B8%2B...%2B2000%29-1%2B4%2B7%2B...1999+%282000-2%29%2F3%2B1-1%3D666%E8%A7%A3%E6%B3%95%E4%B8%80%3B%282%2B1999%29%2B%285%2B1996%29%2B.%2B%281997%2B4%29%2B%282000-1%29%3D2001%2B2001%2B.%2B2001%2B1999%3D2001%2A666%2B1999%3D1332666%2B1999%3D1334665%E8%A7%A3%E6%B3%95%E4%BA%8C%3B%282-1%29%2B%285%2B4%29%2B%288%2B7%29%2B.%282000%2B1999%29+%283999-9%29%2F3%2B1%3D666%3D1%2B%289%2B15%2B21%2B.%2B3999%29%3D1%2B%283999%2B9%29%2A666%2F2)
1.(2+5+8+...+2000)-1+4+7+...1999 (2000-2)/3+1-1=666解法一;(2+1999)+(5+1996)+.+(1997+4)+(2000-1)=2001+2001+.+2001+1999=2001*666+1999=1332666+1999=1334665解法二;(2-1)+(5+4)+(8+7)+.(2000+1999) (3999-9)/3+1=666=1+(9+15+21+.+3999)=1+(3999+9)*666/2
1.(2+5+8+...+2000)-1+4+7+...1999 (2000-2)/3+1-1=666
解法一;(2+1999)+(5+1996)+.+(1997+4)+(2000-1)
=2001+2001+.+2001+1999
=2001*666+1999
=1332666+1999
=1334665
解法二;(2-1)+(5+4)+(8+7)+.(2000+1999) (3999-9)/3+1=666
=1+(9+15+21+.+3999)
=1+(3999+9)*666/2
=1+1334664
=1334665
2,边长为1的正方形那道题
宽 长 面积 是否超过
1 2 2 没超过
2 4 8 没超过
3 6 18 没超过
4 8 32 没超过
5 10 50 没超过
6 12 72 没超过
7 14 98 没超过
8就不行了,所以一共7个
3,求第80个是什么的那道题
437986437986437986.
通过观察发现,437986为一个周期,这个周期有六个数.第80个
80/6=13.2
代表已经过了13个周期,到了下一个周期的第二个,就是3
1.(2+5+8+...+2000)-1+4+7+...1999 (2000-2)/3+1-1=666解法一;(2+1999)+(5+1996)+.+(1997+4)+(2000-1)=2001+2001+.+2001+1999=2001*666+1999=1332666+1999=1334665解法二;(2-1)+(5+4)+(8+7)+.(2000+1999) (3999-9)/3+1=666=1+(9+15+21+.+3999)=1+(3999+9)*666/2
我好感动啊