Odpowiedź :
a)
[tex]0.84 = \frac{84}{100} = \frac{84 \div 4}{100 \div 4} = \frac{21}{25} [/tex]
[tex]0.4 = \frac{4}{10} = \frac{4 \div 2}{10 \div 2} = \frac{2}{5} [/tex]
b)
[tex] \frac{99}{10} = 9 \frac{9}{10} = 9.9[/tex]
[tex] \frac{5}{10} = 0.5[/tex]