几道小学六年级奥数题(简便运算)1/1*3+1/3*5+1/5*7+……+1/47*49== 1/2*5+1/3*5+1/8*11+……+1/20*23== 3/4+7/12-9/20+11/30-13/42== 2002/1*3+2002/3*5+2002/5*7+2002/7*9+2002/9*11==最好写上过程,解题思路.
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/23 13:06:36
![几道小学六年级奥数题(简便运算)1/1*3+1/3*5+1/5*7+……+1/47*49== 1/2*5+1/3*5+1/8*11+……+1/20*23== 3/4+7/12-9/20+11/30-13/42== 2002/1*3+2002/3*5+2002/5*7+2002/7*9+2002/9*11==最好写上过程,解题思路.](/uploads/image/z/69354-18-4.jpg?t=%E5%87%A0%E9%81%93%E5%B0%8F%E5%AD%A6%E5%85%AD%E5%B9%B4%E7%BA%A7%E5%A5%A5%E6%95%B0%E9%A2%98%28%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97%291%2F1%2A3%2B1%2F3%2A5%2B1%2F5%2A7%2B%E2%80%A6%E2%80%A6%2B1%2F47%2A49%3D%3D+1%2F2%2A5%2B1%2F3%2A5%2B1%2F8%2A11%2B%E2%80%A6%E2%80%A6%2B1%2F20%2A23%3D%3D+3%2F4%2B7%2F12-9%2F20%2B11%2F30-13%2F42%3D%3D+2002%2F1%2A3%2B2002%2F3%2A5%2B2002%2F5%2A7%2B2002%2F7%2A9%2B2002%2F9%2A11%3D%3D%E6%9C%80%E5%A5%BD%E5%86%99%E4%B8%8A%E8%BF%87%E7%A8%8B%2C%E8%A7%A3%E9%A2%98%E6%80%9D%E8%B7%AF.)
几道小学六年级奥数题(简便运算)1/1*3+1/3*5+1/5*7+……+1/47*49== 1/2*5+1/3*5+1/8*11+……+1/20*23== 3/4+7/12-9/20+11/30-13/42== 2002/1*3+2002/3*5+2002/5*7+2002/7*9+2002/9*11==最好写上过程,解题思路.
几道小学六年级奥数题(简便运算)
1/1*3+1/3*5+1/5*7+……+1/47*49
=
=
1/2*5+1/3*5+1/8*11+……+1/20*23
=
=
3/4+7/12-9/20+11/30-13/42
=
=
2002/1*3+2002/3*5+2002/5*7+2002/7*9+2002/9*11
=
=
最好写上过程,解题思路.
几道小学六年级奥数题(简便运算)1/1*3+1/3*5+1/5*7+……+1/47*49== 1/2*5+1/3*5+1/8*11+……+1/20*23== 3/4+7/12-9/20+11/30-13/42== 2002/1*3+2002/3*5+2002/5*7+2002/7*9+2002/9*11==最好写上过程,解题思路.
1/1*3+1/3*5+1/5*7+……+1/47*49
= 1/2(1-1/3)+.1/2(1/47-1/49)
= 1/2(1-1/3+1/3-1/5+.+1/47-1/49)
=24/49
1/2*5+1/3*5+1/8*11+……+1/20*23
=
=
3/4+7/12-9/20+11/30-13/42
=(1-1/4+1/4+1/3-1/4-1/5+1/5+1/6-1/6-1/7)
= 1+1/3-1/4-1/7
=79/84
2002/1*3+2002/3*5+2002/5*7+2002/7*9+2002/9*11
=2002(1/1*3+1/3*5+...+1/9*11)
=2002[1/2(1-1/3)+1/2(1/3-1/5)+...+1/2(1/9-1/11)
=2002*5/11
=910