\[\boxed{\mathbf{1}\mathbf{.69}}\]
\[\textbf{а)}\ 7 + 9 = 16\]
\[14 + 8 = 22\]
\[28 + 7 = 35\]
\[16 + 5 = 21\]
\[43 + 0 = 43\]
\[\textbf{б)}\ 14 - 6 = 8\]
\[17 - 9 = 8\]
\[13 - 7 = 6\]
\[16 - 8 = 8\]
\[32 - 0 = 32\]
\[\textbf{в)}\ 6 \cdot 7 = 42\]
\[9 \cdot 4 = 36\]
\[8 \cdot 8 = 64\]
\[5 \cdot 9 = 45\]
\[9 \cdot 6 = 54\]
\[\textbf{г)}\ 72\ :9 = 8\]
\[48\ :6 = 8\]
\[56\ :7 = 8\]
\[81\ :9 = 9\]
\[40\ :8 = 5\]