a)
[tex] \frac{1}{3} = \frac{5}{15} [/tex]
[tex] \frac{2}{5} = \frac{6}{15} [/tex]
[tex] \frac{1}{3} + \frac{2}{5} = \frac{5}{15} + \frac{6}{15} = \frac{11}{15} [/tex]
b)
[tex] \frac{5}{7} = \frac{20}{28} [/tex]
[tex] \frac{1}{4} = \frac{7}{28} [/tex]
[tex] \frac{5}{7} + \frac{1}{4} = \frac{20}{28} + \frac{7}{28} = \frac{27}{28} [/tex]
c)
[tex] \frac{1}{6} = \frac{5}{30} [/tex]
[tex] \frac{3}{5} = \frac{18}{30} [/tex]
[tex] \frac{1}{6} + \frac{3}{5} = \frac{5}{30} + \frac{18}{30} = \frac{23}{30} [/tex]
Myślę że pomogłem ;)
