\(\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}+\frac{1}{243}\)
\(=\frac{81}{243}+\frac{27}{243}+\frac{9}{243}+\frac{3}{243}+\frac{1}{243}\)
\(=\frac{121}{243}\)
mk ko bít đúng hay ko nữa có gì mấy bạn góp ý cho mình nhé ! Thanks
ta có : \(\frac{1}{3}\left(1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}\right)\)
=\(\frac{1}{3}\left(\frac{81+27+9+1}{81}\right)\)
=\(\frac{1}{3}\cdot\frac{118}{81}\)
=\(\frac{118}{243}\)