a)
[tex] \frac{31 + 25}{56 - 49} = \frac{56}{7} = 8[/tex]
b)
[tex] \frac{4.2 + 2.43}{0.5 \times 6} = \frac{6.63}{3} = 2.21[/tex]
c)
[tex]2 \frac{3}{5} + \frac{1}{10} = 2 \frac{6}{10} + \frac{1}{10} = 2 \frac{7}{10} [/tex]
d)
[tex]1 \frac{2}{5} \times \frac{5}{7} = \frac{7}{5} \times \frac{5}{7} = 1[/tex]
e)
[tex]3 \frac{7}{15} - 2 \frac{1}{5} = 3 \frac{7}{15} - 2 \frac{3}{15} = 1 \frac{4}{15} [/tex]
f)
[tex] \frac{8}{9} \div \frac{4}{27} = \frac{8}{9} \times \frac{27}{4} = \frac{2}{1} \times \frac{3}{1} = 6[/tex]
Myślę że pomogłem ;)