(1/2×3)+(2/3×5)+(3/5×8)+(4/8×12)+(5/12×17)+(6/17×23)+(7/23×30)=?

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/03 21:08:36
(1/2×3)+(2/3×5)+(3/5×8)+(4/8×12)+(5/12×17)+(6/17×23)+(7/23×30)=?

(1/2×3)+(2/3×5)+(3/5×8)+(4/8×12)+(5/12×17)+(6/17×23)+(7/23×30)=?
(1/2×3)+(2/3×5)+(3/5×8)+(4/8×12)+(5/12×17)+(6/17×23)+(7/23×30)=?

(1/2×3)+(2/3×5)+(3/5×8)+(4/8×12)+(5/12×17)+(6/17×23)+(7/23×30)=?
(1/2×3)+(2/3×5)+(3/5×8)+(4/8×12)+(5/12×17)+(6/17×23)+(7/23×30)
=1/2-1/3+1/3-1/5+1/5-1/8+1/8-1/12+1/12-1/17+1/17-1/23+1/23-1/30
=1/2-1/30
=7/15