[tex](2^{2n} \times 2) \times (5^{2n} \times 5^3)= \\
=2^{2n}\times 2^1 \times 5^{2n} \times 5^{1+2}= \\
=2^{2n+1} \times 5^{2n} \times 5^1 \times 5^2}= \\
=2^{2n+1} \times 5^{2n+1} \times 5^2}= \\
=(2 \times 5)^{2n+1} \times 5^2}=10^{2n+1} \times 25}=25 \underbrace{00000000...0000}_{ 2n+1~zerouri} \\ \\
\texttt{Numarul este 25 urmat de 2n+1 zerouri.} \\
\Longrightarrow ~~ \texttt{Numarul are 2n+1~zerouri, si in total are 2n+3 cifre } [/tex]
