Các câu hỏi tương tự
a=1/2+1/6+1/12+1/20+1/30+...1/n
tim n biet a=39/40
A= 1/2+1/6+1/12+20+1/30+....+1/n
biet A=39/40 tim n
cho a =1/2+1/6+1/12+1/20+1/30+.....+1/n biet a +39/40
A=1/2+1/6+1/12+1/20+...1/n Biet A=38/40 Tim n
Cho A= 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + ........ + 1/n = 39/40
Cho A = 1/2 + 1/6 + 1/12 + 1/20 +1/30 + ....... + 1/n . Biết A =39/40.Tìm n.
Cho a= 1/2 + 1/6+ 1/12+ 1/20 + 1/30+...1/n.Tìm n biết a = 39/40
Cho a= 1/2+1/6 +1/12+1/20+1/30+...1/n
Biết a= 39/40 .Tìm n
Cho A = 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + ... + 1/n
Biết A = 39/40. Tìm n