Question

  Giúp

Answer 1

a: =1-1/2+1/2-1/3+...+1/49-1/50

=1-1/50

=49/50

b: =1-1/3+1/3-1/5+...+1/37-1/39

=1-1/39

=38/39

c: =1/3-1/5+1/5-1/7+...+1/37-1/39

=1/3-1/39

=12/39=4/13