1/20+1/30+1/42+.+1/132+1/156=1-1/2-1/4-1/8-1/16-1/32-.1/1024=还有一道:2+3 1/6+5 1/12+7 1/20+11 1/30+13 1/42=还有:2/1×3×5+2/3×5×7+2/5×7×9+2/7×9×11=2/11×13+2/13×15+2/15×17+2/17×19+2/19×21=
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/27 11:58:32
![1/20+1/30+1/42+.+1/132+1/156=1-1/2-1/4-1/8-1/16-1/32-.1/1024=还有一道:2+3 1/6+5 1/12+7 1/20+11 1/30+13 1/42=还有:2/1×3×5+2/3×5×7+2/5×7×9+2/7×9×11=2/11×13+2/13×15+2/15×17+2/17×19+2/19×21=](/uploads/image/z/5154923-11-3.jpg?t=1%2F20%2B1%2F30%2B1%2F42%2B.%2B1%2F132%2B1%2F156%3D1-1%2F2-1%2F4-1%2F8-1%2F16-1%2F32-.1%2F1024%3D%E8%BF%98%E6%9C%89%E4%B8%80%E9%81%93%3A2%2B3+1%2F6%2B5+1%2F12%2B7+1%2F20%2B11+1%2F30%2B13+1%2F42%3D%E8%BF%98%E6%9C%89%3A2%2F1%C3%973%C3%975%2B2%2F3%C3%975%C3%977%2B2%2F5%C3%977%C3%979%2B2%2F7%C3%979%C3%9711%3D2%2F11%C3%9713%2B2%2F13%C3%9715%2B2%2F15%C3%9717%2B2%2F17%C3%9719%2B2%2F19%C3%9721%3D)
1/20+1/30+1/42+.+1/132+1/156=1-1/2-1/4-1/8-1/16-1/32-.1/1024=还有一道:2+3 1/6+5 1/12+7 1/20+11 1/30+13 1/42=还有:2/1×3×5+2/3×5×7+2/5×7×9+2/7×9×11=2/11×13+2/13×15+2/15×17+2/17×19+2/19×21=
1/20+1/30+1/42+.+1/132+1/156=
1-1/2-1/4-1/8-1/16-1/32-.1/1024=
还有一道:2+3 1/6+5 1/12+7 1/20+11 1/30+13 1/42=
还有:2/1×3×5+2/3×5×7+2/5×7×9+2/7×9×11=
2/11×13+2/13×15+2/15×17+2/17×19+2/19×21=
1/20+1/30+1/42+.+1/132+1/156=1-1/2-1/4-1/8-1/16-1/32-.1/1024=还有一道:2+3 1/6+5 1/12+7 1/20+11 1/30+13 1/42=还有:2/1×3×5+2/3×5×7+2/5×7×9+2/7×9×11=2/11×13+2/13×15+2/15×17+2/17×19+2/19×21=
1/20+1/30+1/42+.+1/132+1/156=1/4-1/5+1/5-1/6+1/6-1/7+...-1/12+1/12-1/13=1/4-1/13=9/52(裂项相消)
1-1/2-1/4-1/8-1/16-1/32-.1/1024=1-(1/2+1/4+1/8+1/16+...+1/1024)=1-1/2[1-(1/2)^10]/(1-1/2)=1-(1-1/1024)=1/1024
2+3 1/6+5 1/12+7 1/20+11 1/30+13 1/42=2+3+5+7+11+13+1/6+1/12+1/20+1/30+1/42=41+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7=41+1/2-1/7=41 5/14(还是裂项相消)
第1题是365
2是1536
3是106
4是584
5是1536