[tex]\displaystyle\\
\left(0,4+ \frac{3}{7} \right):0,5= \\\\\\
=\left( \frac{4}{10} + \frac{3}{7} \right): \frac{1}{2} = \\\\\\
=\left( \frac{2}{5} + \frac{3}{7} \right): \frac{1}{2} = \\\\\\
=\frac{7\times 2 + 5\times3}{5\times 7}: \frac{1}{2} = \\\\\\
=\frac{14 + 15}{35} : \frac{1}{2} = \frac{29}{35} : \frac{1}{2} = \frac{29}{35} \times \frac{2}{1} = \frac{29\times 2}{35} = \boxed{\frac{58}{35}} [/tex]