a) 3$$\frac{2}{7}$$ +4$$\frac{3}{7}$$ = (3+4) + ($$\frac{2}{7}$$+$$\frac{3}{7}$$) = 7 + $$\frac{5}{7}$$ = 7$$\frac{5}{7}$$
б) 6$$\frac{3}{8}$$+2$$\frac{5}{8}$$ = (6+2) + ($$\frac{3}{8}$$+$$\frac{5}{8}$$) = 8 + $$\frac{8}{8}$$ = 8 + 1 = 9
в) 4$$\frac{5}{12}$$ +3$$\frac{11}{12}$$ = (4+3) + ($$\frac{5}{12}$$+$$\frac{11}{12}$$) = 7 + $$\frac{16}{12}$$ = 7 + $$\frac{4}{3}$$ = 7 + 1$$\frac{1}{3}$$ = 8$$\frac{1}{3}$$
г) 9 + 1$$\frac{5}{6}$$ = (9+1) + $$\frac{5}{6}$$ = 10 + $$\frac{5}{6}$$ = 10$$\frac{5}{6}$$
Ответ: a) 7$$\frac{5}{7}$$; б) 9; в) 8$$\frac{1}{3}$$; г) 10$$\frac{5}{6}$$