\[\boxed{\mathbf{1}.}\]
\[1)\ \left( \frac{3}{5} + 4 \right) \cdot 5 = \frac{3}{5} \cdot 5 + 4 \cdot 5 =\]
\[= 3 + 20 = 23\]
\[2)\ 9 \cdot \left( \frac{1}{3} + 2 \right) = 9 \cdot \frac{1}{3} + 9 \cdot 2 =\]
\[= 3 + 18 = 21\]
\[3)\ \frac{1}{7}\ :2 = \frac{1}{7} \cdot \frac{1}{2} = \frac{1}{14}\]
\[4)\ \frac{4}{5}\ :4 = \frac{4}{5} \cdot \frac{1}{4} = \frac{1}{5}\]
\[5)\ \frac{3}{11}\ :\frac{3}{8} = \frac{3}{11} \cdot \frac{8}{3} = \frac{8}{11}\]
\[6)\ \frac{4}{5}\ :0,8 = 0,8\ :0,8 = 1\]
\[\boxed{\mathbf{2.}}\]
\[1)\ 5\]
\[2) - 5\]
\[3)\ 5\]
\[4) - 5\]
\[5)\ равноудалены\]
\[6) - 2\]
\[\boxed{\mathbf{3.}}\]
\[- 1\ и\ 1;\ \ - 2\ и\ 2;\ - 3\ и\ 3;\]
\[\ \ - 4\ и\ 4;\ - 5\ и\ 5.\]
\[\boxed{\mathbf{4}.}\]
\[1)\ B( - 7);\]
\[2)\ B(4,86).\]