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) $frac{7}{34} + frac{5}{51} = frac{21}{102} + frac{10}{102} = frac{31}{102}$