Question

Tính tổng sau:

1/1.2+1/2.3+1/3.4+...+1/99.100

Ai k mik mik k lại

Answer 1

1/1.2+1/2.3+1/3.4+...+1/99.100

= 1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100

=1-1/100

=100/100-1/100

=99/100

Answer 2

Ta có: 1/1.2 + 1/2.3 + 1/3.4 +...+ 1/99.100

= 1/1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 +...+ 1/99 - 1/100

= 1 - 1/100

= 99/100

Đúng 100%