nyatakan dalam notasi sigma 3/15 + 8/12 + 15/27 + ...... + 120/69

[tex]
\text{Perhatikan bahwa}\\
\frac{3}{15}+\frac{8}{12}+\frac{15}{27}+\ldots+\frac{120}{69}\\
=\frac{1\cdot3}{15}+\frac{2\cdot4}{12}+\frac{3\cdot5}{27}+\ldots+\frac{10\cdot12}{69}\\
=\frac{1}{3}\left(\frac{1\cdot3}{5}+\frac{2\cdot4}{4}+\frac{3\cdot5}{9}+\ldots+\frac{10\cdot12}{23}\right)\\
[/tex]