\[\boxed{\mathbf{9.}}\]
\[\textbf{а)}\ 36 + 3 = 39\]
\[42 + 5 = 47\]
\[67 - 3 = 62\]
\[82 - 2 = 84\]
\[\textbf{б)}\ 45 + 4 + 1 = 49 + 1 = 50\]
\[63 + 6 + 1 = 69 + 1 = 70\]
\[38 - 7 - 1 = 31 - 1 = 30\]
\[56 - 5 - 1 = 51 - 1 = 50\]