Zadanie 1
[tex]\frac{1}{4}+\frac{1}{8}=\frac{1\cdot2}{4\cdot2}+\frac{1}{8}=\frac{2}{8}+\frac{1}{8}=\frac{3}{8}\\\\1-\frac{3}{8}=\frac{8}{8}-\frac{3}{8}=\frac{5}{8}[/tex]
Odp. 5/8 tortu nie zostało zjedzone.
Zadanie 2
[tex]7\frac{4}{5}-2\frac{3}{4}=7\frac{4\cdot4}{5\cdot4}-2\frac{3\cdot5}{4\cdot5}=7\frac{16}{20}-2\frac{15}{20}=5\frac{1}{2}\\\\2\frac{1}{5}\cdot4\frac{1}{6}=\frac{2\cdot5+1}{5}\cdot\frac{4\cdot6+1}{6}=\frac{10+1}{5}\cdot\frac{24+1}{6}=\frac{11}{\not5_1}\cdot\frac{\not25^5}{6}=\frac{55}{6}=9\frac{1}{6}[/tex]
Zadanie 3
[tex]2\frac{2}{5}:1\frac{2}{10}=\frac{2\cdot5+2}{5}:\frac{1\cdot10+2}{10}=\frac{10+2}{5}:\frac{10+2}{10}=\frac{12}{5}:\frac{12}{10}=\frac{\not12^1}{\not5_1}\cdot\frac{\not10^2}{\not12_1}=2\\\\3\frac{2}{7}+2\frac{3}{4}=3\frac{2\cdot4}{7\cdot4}+2\frac{3\cdot7}{4\cdot7}=3\frac{8}{28}+2\frac{21}{28}=5\frac{29}{28}=6\frac{1}{28}[/tex]
