\[\boxed{\mathbf{569\ (569).}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ 12x = 7\]
\[x = 7\ :12\]
\[x = 0,58(3)\]
\[x \approx 0,58.\]
\[2)\ 5\ :x = 8\]
\[x = 5\ :8\]
\[x = 0,625\]
\[x \approx 0,63.\]
\[3)\ 7x = 16\]
\[x = 16\ :7\]
\[x = 2,2857\ldots\]
\[x \approx 2,29.\]
\[4)\ \frac{3}{8}x = 1\frac{9}{16}\]
\[x = \frac{25}{16}\ :\frac{3}{8}\]
\[x = 4,1(6)\]
\[x \approx 4,17.\]