\[\boxed{\mathbf{Вариант\ 1.}}\]
\[\boxed{\mathbf{1.}}\]
\[(18 + 6)\ :6 = 3 + 1 = 4\]
\[(12 + 27)\ :3 = 4 + 9 = 13\]
\[(16 + 24)\ :8 = 2 + 3 = 5\]
\[(20 + 28)\ :8 = 48\ :8 = 6\]
\[(15 + 15)\ :6 = 30\ :6 = 5\]
\[(21 + 31)\ :4 = 52\ :4 = 13\]
\[\boxed{\mathbf{2.}}\]
\[1)\ 57\ :3 = (30 + 27)\ :3 =\]
\[= 10 + 9 = 19\]
\[56\ :2 = (40 + 16)\ :2 =\]
\[= 20 + 8 = 28\]
\[2)\ 55\ :5 = 11\]
\[64\ :2 = 32\]
\[45\ :3 = 15\]
\[84\ :6 = 14\]
\[96\ :3 = 32\]
\[78\ :6 = 13\]
\[\boxed{\mathbf{3.}}\]
\[1)\ 90\ :5 = 18\]
\[76\ :4 = 19\]
\[2)\ 72\ :18 = 4\]
\[4 \cdot 18 = 72\]
\[42\ :14 = 3\]
\[3 \cdot 14 = 42\]
\[95\ :19 = 5\]
\[19 \cdot 5 = 95\]
\[\boxed{\mathbf{4.}}\]
\[17 \cdot 4 = 68\]
\[68\ :4 = 17\]
\[26 \cdot 3 = 78\]
\[78\ :26 = 3\]
\[37 \cdot 2 = 74\]
\[74\ :37 = 2\]