Question

1/1.3+1/3.4+1/4.5+....+1/99.100

Giai giùm mình rõ ràng cho like

 

Answer 1

A = 1/2 - 1/3 + 1/3 -1/4 + 1/4 -1/5 + ...+ 1/98 - 1/99 + 1/99 - 1/100 
A = 1/2 - 1/100 = 49/100