\[\boxed{\mathbf{3.}\mathbf{176}}\]
\[\textbf{а)}\ 63 + x = 164\]
\[x = 164 - 63\]
\[x = 101.\]
\[\textbf{б)}\ 2y + 29 = 79\]
\[2y = 79 - 29\]
\[y = 50\ :2\]
\[y = 25.\]
\[\textbf{в)}\ 27a + 54 = 496 - 37\]
\[27a + 54 = 459\]
\[27a = 459 - 54\]
\[27a = 405\]
\[a = 405\ :27\]
\[a = 15.\]
\[\textbf{г)}\ 2m - 34 = 138\]
\[2m = 138 + 34\]
\[m = 172\ :2\]
\[m = 86.\]
\[\textbf{д)}\ 3p - 96 = 274 - 130\]
\[3p - 96 = 144\]
\[3p = 144 + 96\]
\[p = 240\ :3\]
\[p = 80.\]