a)
[tex] \frac{3}{7} \times \frac{5}{9} = \frac{1}{7} \times \frac{5}{3} = \frac{5}{21} [/tex]
[tex] \frac{4}{3} \times \frac{7}{16} = \frac{1}{3} \times \frac{7}{4} = \frac{7}{21} = \frac{1}{3} [/tex]
[tex] \frac{6}{11} \times \frac{5}{9} = \frac{2}{11} \times \frac{5}{3} = \frac{10}{33} [/tex]
b)
[tex] \frac{8}{21} \times \frac{7}{12} = \frac{2}{3} \times \frac{1}{3} = \frac{2}{9} [/tex]
[tex] \frac{5}{6} \times \frac{9}{20} = \frac{1}{2} \times \frac{3}{4} = \frac{3}{8} [/tex]
[tex] \frac{4}{7} \times \frac{21}{36} = \frac{1}{1} \times \frac{3}{9} = \frac{3}{9} = \frac{1}{3} [/tex]
Myślę że pomogłem ;)
