\[\boxed{\mathbf{30.}}\]
\[\textbf{а)}\ 36 - 16 = 20\]
\[62 - 32 = 30\]
\[55 - 15 = 40\]
\[47 - 45 = 2\]
\[29 - 26 = 3\]
\[83 - 82 = 1\]
\[\textbf{б)}\ 65 - (14 + 31) = 65 - 45 =\]
\[= 20\]
\[78 - 35 + 26 = 23 + 26 = 49\]
\[97 - (59 - 54) = 97 - 5 = 92\]