Question

[angle le]

1/1*2+1/2*3+1/3*4+...................+1/2005*2006

giúp tớ với!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1

[Trần Thị Minh Ngọc]

1/(1*2)+1/(2*3)+1/(3*4)+...+1/(2005*2006)

=1/1-1/2+1/2-1/3+1/3-1/4+...+1/2005-1/2006

=1-1/2006

=2005/2006

Answer 2

[Đức Nguyễn Minh]

d

ong y