八分之一连继加到八分之三十九怎样简便计算?

2025-02-22 21:36:37
推荐回答(1个)
回答1:

1/8+2/8+3/8+......+38/8+39/8
=1/8(1+2+3+......+38+39)
=1/8×(1+39)×39÷2
=5×39÷2
=195/2