Witaj :)
1]
[tex]1\dfrac{1}{7}+\dfrac{3}{4}=1\dfrac{1\cdot4}{7\cdot4}+\dfrac{3\cdot7}{4\cdot7}=1\dfrac{4}{28}+\dfrac{21}{28}=\boxed{1\frac{25}{28}}\\[/tex]
2]
[tex]2\dfrac{3}{4}-\dfrac{1}{2}=2\dfrac{3}{4}-\dfrac{1\cdot2}{2\cdot2}=2\dfrac{3}{4}-\dfrac{2}{4}=\boxed{2\frac{1}{4}}\\[/tex]
