\(F=1\dfrac{1}{5}\times1\dfrac{1}{6}\times1\dfrac{1}{7}\times\cdot\cdot\cdot\times1\dfrac{1}{2019}\times1\dfrac{1}{2020}\)
\(F=\dfrac{6}{5}\times\dfrac{7}{6}\times\dfrac{8}{7}\times\cdot\cdot\cdot\times\dfrac{2020}{2019}\times\dfrac{2021}{2020}\)
\(F=\dfrac{6\times7\times8\times\cdot\cdot\cdot\times2020\times2021}{5\times6\times7\times\cdot\cdot\cdot\times2019\times2020}\)
\(F=\dfrac{2021}{5}\)
| \(Huyền\) |
\(f=1^1_5\times1^1_6\times1^1_7\times......\times1^1_{2019}\times1^1_{2022}\)
\(f=\dfrac{6}{5}\times\dfrac{7}{6}\times\dfrac{8}{7}\times....\times\dfrac{2020}{2019}\times\dfrac{2021}{2020}\)
\(f=\dfrac{6\times7\times8\times....\times2020\times2021}{5\times6\times7\times.....\times2019\times2020}\)
\(f=\dfrac{2021}{5}\)
\(#Tarus\)
