Thông cảm , phép  tính dài quá các bạn nhé

1.2.3.4 + 2.3.4.5 + 3.4.5.6 + 4.5.6.7 + … + 422485.422486.422487.422488 = (422485.422486.422487.422488.422489−0.1.2.3.4):5 = 2692134456084412195259330928

$\begin{array}{l}
1.2.3.4 + 2.3.4.5 + ... + 422485.422486.422487.422488\\
 = \dfrac{{422485.422486.422487.422488.422489}}{5} = {\rm{2692134456084412195259330928}}
\end{array}$

$\begin{array}{l}
A = {\bf{1}}.{\bf{2}}.{\bf{3}}.{\bf{4}}{\rm{ }} + {\rm{ }}{\bf{2}}.{\bf{3}}.{\bf{4}}.{\bf{5}}{\rm{ }} + {\rm{ }} \ldots {\rm{ }} + {\rm{ }}{\bf{422485}}.{\bf{422486}}.{\bf{422487}}.{\bf{422488}}\\
A = \dfrac{{422485.422486.422487.422488.422489 - 0.1.2.3.4}}{5} = \dfrac{{{\rm{13460672280422060976296654640}}}}{5}\\
A = {\rm{2692134456084412195259330928}}
\end{array}$