1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+...1/39*40=?(化简!)1 1 1 1 1___+___+___+___+……+___=?1x2 2x3 3x4 4x5 39x40

来源：学生作业帮助网 编辑：作业帮 时间：2024/05/04 04:38:40
1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+...1/39*40=?(化简!)1 1 1 1 1___+___+___+___+……+___=?1x2 2x3 3x4 4x5 39x40

1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+...1/39*40=?(化简!)1 1 1 1 1___+___+___+___+……+___=?1x2 2x3 3x4 4x5 39x40
1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+...1/39*40=?(化简!)
1 1 1 1 1
___+___+___+___+……+___=?
1x2 2x3 3x4 4x5 39x40

1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+...1/39*40=?(化简!)1 1 1 1 1___+___+___+___+……+___=?1x2 2x3 3x4 4x5 39x40
1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+...1/39*40
=(1-1/2)+(1/2-1/3)+.+(1/39-1/40)
=1-1/40
=39/40

1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+...1/39*40
=(1-1/2)+(1/2-1/3)+....+(1/39-1/40)
=1-1/40
=39/40