Đáp án:
1349041099
Giải thích các bước giải:
$\begin{array}{l}
4 = 4 + 0 + .. + 0\left( {2006\,c/s\,0} \right)\, \Rightarrow \,co\,1\,so\,thoa\,man\,:\,400...00\\
= 3 + 1 + 0 + .. + 0\,\left( {2005\,c/s\,0} \right) \Rightarrow co\,\,\,C_{2007}^1.2\,\,\,so\,tm\\
= 2 + 2 + 0 + ... + 0\,\left( {2005\,c.s\,0} \right) \Rightarrow co\,\,C_{2007}^1\,so\\
= 2 + 1 + 1 + 0 + .. + 0\left( {2004\,c/s\,0} \right) \Rightarrow co\,\,A_{2007}^2:2.2 = A_{2007}^2\,\,so\\
= 1 + 1 + 1 + 1 + 0 + ... + 0\,\left( {2003\,c/s\,0} \right) \Rightarrow co\,\,C_{2007}^3\,\,\,\,so\\
VAy\,co:1 + C_{2007}^1.2\, + C_{2007}^1 + A_{2007}^2 + C_{2007}^3 = 1349401099
\end{array}$
