Решение:

а) $$4\frac{2}{9} + 3\frac{5}{18} = 4 + 3 + \frac{2}{9} + \frac{5}{18} = 7 + \frac{4}{18} + \frac{5}{18} = 7 + \frac{9}{18} = 7 + \frac{1}{2} = 7\frac{1}{2}$$ б) $$3\frac{5}{12} + 4\frac{7}{9} = 3 + 4 + \frac{5}{12} + \frac{7}{9} = 7 + \frac{15}{36} + \frac{28}{36} = 7 + \frac{43}{36} = 7 + 1\frac{7}{36} = 8\frac{7}{36}$$ в) $$7\frac{11}{12} + 1\frac{3}{8} = 7 + 1 + \frac{11}{12} + \frac{3}{8} = 8 + \frac{22}{24} + \frac{9}{24} = 8 + \frac{31}{24} = 8 + 1\frac{7}{24} = 9\frac{7}{24}$$ г) $$4\frac{3}{8} + 2\frac{4}{11} = 4 + 2 + \frac{3}{8} + \frac{4}{11} = 6 + \frac{33}{88} + \frac{32}{88} = 6 + \frac{65}{88} = 6\frac{65}{88}$$ д) $$6\frac{5}{11} + 5 = 6 + 5 + \frac{5}{11} = 11 + \frac{5}{11} = 11\frac{5}{11}$$ е) $$7\frac{3}{7} + \frac{5}{21} = 7 + \frac{3}{7} + \frac{5}{21} = 7 + \frac{9}{21} + \frac{5}{21} = 7 + \frac{14}{21} = 7 + \frac{2}{3} = 7\frac{2}{3}$$ ж) $$6 + 4\frac{2}{7} = 6 + 4 + \frac{2}{7} = 10 + \frac{2}{7} = 10\frac{2}{7}$$ з) $$\frac{3}{7} + 3\frac{4}{5} = 3 + \frac{3}{7} + \frac{4}{5} = 3 + \frac{15}{35} + \frac{28}{35} = 3 + \frac{43}{35} = 3 + 1\frac{8}{35} = 4\frac{8}{35}$$

Ответ:

а) $$7\frac{1}{2}$$ б) $$8\frac{7}{36}$$ в) $$9\frac{7}{24}$$ г) $$6\frac{65}{88}$$ д) $$11\frac{5}{11}$$ е) $$7\frac{2}{3}$$ ж) $$10\frac{2}{7}$$ з) $$4\frac{8}{35}$$