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.
a= 1/2 + 1/6 +1/12 + 1/20 +1/30 + .... + 1/n. tìm n biết a= 39/40
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 biet a +39/40
Cho A= 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + ........ + 1/n = 39/40
A=1/2+1/6+1/12+1/20+1/30+...+1/n
Biết A=39/40 tìm n.
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+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