Odpowiedź :
[tex]a) 1 \frac{4}{5}+2\frac{1}{4}= 1 \frac{16}{20}+2\frac{5}{20}=3\frac{21}{20}=4\frac{1}{20}\\\\b) 5\frac{3}{4}-2\frac{6}{7}=5\frac{21}{28}-2\frac{24}{28}=4\frac{49}{28}-2\frac{24}{28}=2\frac{25}{28}[/tex]
[tex]a) 1 \frac{4}{5}+2\frac{1}{4}= 1 \frac{16}{20}+2\frac{5}{20}=3\frac{21}{20}=4\frac{1}{20}\\\\b) 5\frac{3}{4}-2\frac{6}{7}=5\frac{21}{28}-2\frac{24}{28}=4\frac{49}{28}-2\frac{24}{28}=2\frac{25}{28}[/tex]