Question

[Văn Ngọc Hà Anh]

1+\(\frac{1}{3}\)+ \(\frac{1}{9}\)+ \(\frac{1}{27}\)+ \(\frac{1}{81}\)+ \(\frac{1}{243}\)+ \(\frac{1}{729}\)

Answer 1

[Đ𝐚𝐧𝐧 𝐋ê]

=1093/729

ko bt có đung ko nữa

Answer 2

[tranhailien]

a=1 +1/3 +1/3^2 +1/3^3 +1/3^4 +1/3^5+1/3^6

3a=3 +1 +1/3 +1/3^2 + 1/3^3 +...+1/3^5

3a -a=[3 +1 +1/3 +1/3^2 +...+1/3^5] -1 -1/3 -1/3^2 -.........-1/3^6

2a =3- 1/3^6

a=[3-1/3^6] :2