1⼀1×3+1⼀3×5+1⼀5×7+1⼀7×9+1⼀9×11 简便算法

2025-01-07 20:37:36
推荐回答(1个)
回答1:

1/1×3+1/3×5+1/5×7+1/7×9+1/9×11
=(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11)÷2
=(1-1/11)÷2
=10/11÷2
=5/11