Question

Bài 3: Tính hợp lý tổng sau

Answer 1

Giải:

A= 1/1.2 +1/2.3 +1/3.4 +...+1/49.50

A= 1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4+...+1/49 - 1/50

A= 1 - 1/50

A= 50/50 - 1/50

A= 49/50

Answer 2

A = 1/1.2 + 1/2.3 + 1/3.4 + ... + 1/49.50

A = 1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + ... + 1/49 - 1/50

A = 1 - 1/50

A = 50/50 - 1/50

A = 49/50