\[\boxed{\mathbf{Вариант\ 1.}}\]
\[\boxed{\mathbf{1.}}\]
\[5 \cdot 4 > 5 + 5 + 4 + 5\]
\[6 + 6 + 6 + 6 > 6 \cdot 3\]
\[1 \cdot 43 < 1 + 43\]
\[8 \cdot 4 > 8 + 4\]
\[10 \cdot 2 > 12\]
\[0 \cdot 100 < 100 - 1\]
\[\boxed{\mathbf{2.}}\]
\[2 \cdot 9 = 18\]
\[6 \cdot 2 = 12\]
\[14\ :2 = 7\]
\[16\ :8 = 2\]
\[60 - (37 - 7) = 60 - 30 = 30\]
\[89 - 56 + 20 = 33 + 20 = 53\]
\[\boxed{\mathbf{3.}}\]
\[12\ :6 = 2\ (полки) - заняли\ \]
\[все\ кассеты.\]
\[Ответ:2\ полки.\]
\[\boxed{\mathbf{4.}}\]
\[1)\]
\[2)\ CB = 8\ :2 = 4\ см.\]
\[\boxed{\mathbf{5.}}\]
\[62 - 30 + 8 = 40\]
\[46 - 10 - 6 = 30\]