Question

[Nguyễn Minh Hiếu]

A=1/1.2+1/2.3+1/3.4+....+1/50.51

B=2/3.5+2/5.7+2/7.9+....+2/51.53

C=6/4.7+6/7.10+6/10.13+....+6/73.76

GIÚP MIK VỚI CẢM ƠN MN.

Answer 1

[thắng]

A = 1 /1.2 + 1/ 2.3 + 1 /3.4 + . . . + 1/ 49.50 + 1/ 50.51

 A = 2 − 1/ 1.2 + 3 − 2 /2.3 + 4 − 3 /3.4 + . . . + 50 − 49 /49.50 + 51 − 50/ 50.51

A = 1 − 1/ 2 + 1/ 2 − 1 /3 + 1 /3 − 1/ 4 + . . . + 1 /50 − 1 /51

A=1-1/51

A=50/51

Answer 2

[Nguyễn Minh Hiếu]

Cảm ơn bn