[tex]4^7 \times 5^{12} \times 3^8 = \\ \\
=(2^2)^7 \times 5^{12} \times 3^8 = \\ \\
=2^{2\times 7} \times 5^{12} \times 3^8 = \\ \\
=2^{14} \times 5^{12} \times 3^8 = \\ \\
=2^{2+12} \times 5^{12} \times 3^8 = \\ \\
=2^2 \times 2^{12} \times 5^{12} \times 3^8 = \\ \\
= 2^2 \times 3^8 \times 2^{12} \times 5^{12} = \\ \\
= 2^2 \times 3^8 \times (2\times 5)^{12} = \\ \\
= 2^2 \times 3^8 \times 10^{12} ~~~~~\Longrightarrow ~~ \boxed{12~\text{zerouri}} [/tex]
