a)
\frac{5}{6}=\frac{3}{6}+\frac{2}{6}=\frac{1}{2}+\frac{1}{3}
b)
1=\frac{1}{2}+\frac{1}{2}=\frac{1}{2}+\frac{3}{6}=\frac{1}{2}+\frac{2}{6}+\frac{1}{6}=\frac{1}{2}+\frac{1}{3}+\frac{1}{6}
c)
0,7=\frac{7}{10}=\frac{5}{10}+\frac{2}{10}=\frac{1}{2}+\frac{1}{5}
d)
\frac{13}{15}=\frac{26}{30}=\frac{15}{30}+\frac{10}{30}+\frac{1}{30}=\frac{1}{2}+\frac{1}{3}+\frac{1}{30}