Question

[hoàng thùy linh]

tính

C=1/2+5/6+11/12+...+2449/2450

Answer 1

[forever young]

C=1-1/2 +1-1/6 +1-1/12 +.............+1-1/2450

=(1+1+1+.........+1)-(1/2 +1/6 +1/12+..............+1/2450)

=49-(1/1.2 +1/2.3 +1/3.4+ ..................+1/49.50)

=49-(1-1/2 +1/2 -1/3+ 1/3- 1/4+............+1/49 -1/50)

=49-(1-1/50) =49-49/50=2401/50