А)1/6 +1/9 б)2/9 + 5/6 в)2/9 + 3/9 г)3/4 + 6/15 д)2/26 + 3/39 е)7/34 + 5/51;

А) $\frac{1}{6} + \frac{1}{9}= \frac{3}{18} + \frac{2}{18} = \frac{5}{18}$
б) $\frac{2}{9} + \frac{5}{6} = \frac{4}{18} + \frac{15}{18} = \frac{19}{18} =1 \frac{1}{18}$
в) $\frac{2}{9} + \frac{3}{9} = \frac{5}{9}$
г) $\frac{3}{4} + \frac{6}{15} = \frac{45}{60} + \frac{24}{60} = \frac{69}{60} =1 \frac{9}{60} = 1 \frac{3}{20}$
д) $\frac{2}{26} + \frac{3}{39} = \frac{6}{78} + \frac{6}{78}= \frac{12}{78} = \frac{6}{39}$
е) $\frac{7}{34} + \frac{5}{51} = \frac{21}{102} + \frac{10}{102} = \frac{31}{102}$