1/1*2*3+1/2*3*4+1/3*4*5+···+1/11*12*13 简便方法
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/13 12:16:03
![1/1*2*3+1/2*3*4+1/3*4*5+···+1/11*12*13 简便方法](/uploads/image/z/241359-15-9.jpg?t=1%2F1%2A2%2A3%2B1%2F2%2A3%2A4%2B1%2F3%2A4%2A5%2B%C2%B7%C2%B7%C2%B7%2B1%2F11%2A12%2A13+%E7%AE%80%E4%BE%BF%E6%96%B9%E6%B3%95)
x)37226Z&@Hjj@u
O6mSmժ_`gC'{mA4tZ4"@.X3\
Ӄ
b(d$ف< k
1/1*2*3+1/2*3*4+1/3*4*5+···+1/11*12*13 简便方法
1/1*2*3+1/2*3*4+1/3*4*5+···+1/11*12*13 简便方法
1/1*2*3+1/2*3*4+1/3*4*5+···+1/11*12*13 简便方法
1/1*2*3+1/2*3*4+1/3*4*5+···+1/11*12*13
=1/2*(1/1*2-1/2*3)+1/2*(1/2*3-1/3*4)+1/2*(1/3*4-1/4*5)+...+1/2*(1/11*12-1/12*13)
=1/2*(1/1*2-1/12*13)
=1/2*77/156
=77/312