Cześć!
Szczegółowe wyjaśnienie:
a)
[tex]( - \frac{ 8}{9} ) \cdot( - 3 \frac{6}{7} ) = (- \frac{8}{9} ) \cdot ( - \frac{27}{7} ) = 8 \cdot \frac{3}{7} = \frac{24}{7} = 3 \frac{3}{7} [/tex]
b)
([tex]2 \frac{7}{9} ) \cdot1.35 = \frac{25}{9} \cdot \frac{27}{20} =5 \cdot \frac{3}{4} = \frac{15}{4} [/tex]
c)
[tex](3 \frac{1}{4} ) {}^{2} = ( \frac{13}{4} ) {}^{2} = \frac{13 \cdot2}{4 \cdot2} = \frac{169}{16} = 10 \frac{9}{16} [/tex]