Question

tinh 

A=1/1.2+1/2.3+1/3.4+.........1/99.100

Answer 1

A=1-1/2+1/2-1/3+1/3-1/4+.........+1/99-1/100

A=1-1/100

A=99/100

ai k mk      mk k lai 

Answer 2

A=1-1/100

A=99/100

Nha bạn       

Answer 3

A = 1 - 1/2 + 1/2 - 1/3 + ......+ 1/99 - 1/100

A =  1 - 1/100

A = 99/100

Ai k mk mk k lại !