\[\boxed{\mathbf{361\ (361).}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\frac{1^{\backslash 6}}{2}a + \frac{1^{\backslash 4}}{3}a - \frac{1^{\backslash 3}}{4}a =\]
\[= \frac{6 + 4 - 3}{12}a = \frac{7}{12}a\]
\[a = 1\frac{5}{7} = \frac{12}{7}:\]
\[\frac{7}{12}a = \frac{7 \cdot 12}{12 \cdot 7} = 1.\]
\[2)\ \frac{4^{\backslash 3}}{7}b + \frac{5}{21}b - \frac{2^{\backslash 7}}{3}b =\]
\[= \frac{12 + 5 - 14}{21}b = \frac{3}{21}b = \frac{1}{7}b\]
\[b = 2\frac{1}{3} = \frac{7}{3}:\]
\[\frac{1}{7}b = \frac{1 \cdot 7}{7 \cdot 3} = \frac{1}{3}.\]
\[3)\ 1\frac{5^{\backslash 3}}{12}m + 2\frac{7^{\backslash 2}}{18}m - 1\frac{2^{\backslash 4}}{9}m =\]
\[= \left( 1\frac{15}{36} + 2\frac{14}{36} - 1\frac{8}{36} \right)m =\]
\[= 2\frac{21}{36}m = 2\frac{7}{12}m\]
\[m = 1\frac{17}{31} = \frac{48}{31}:\]