Question

1/6+1/66+1/176+1/336+...+1/496.501

Answer 1

1/6+1/66+1/176+....+1/496.501

=1/1.6+1/6.11+1/11.16+....+1/496.501

=(1/5).(5/1.6+5/6.11+5/11.16+....+5/496.501)

=(1/5).(1-1/6+1/6-1/11+1/11-1/16+...+1/496-1/501)

=(1/5).(1-1/501)

=1/5 . 500/501

=100/501

Answer 2

Ta có: 1/6+1/66+1/176+1/336+...+1/496.501

         =1/1.6+1/6.11+1/11.16+1/16.21+...+1/496.501

         =1/5.(5/1.6+5/6.11+5/11.16+5/16.21+...+5/496.501)

         =1/5.(1-1/6+1/6-1/11+1/11-1/16+1/16-1/21+...+1/496-1/501)

         =1/5.(1-1/501)

         =1/5.500/501

         =100/501

Answer 3

đúng không trần hương giang

Answer 4

BANG 100/501