Răspuns :
[tex]\it 9\cdot\dfrac{25}{2}=\dfrac{9\cdot25}{2}=\dfrac{225}{2}\\ \\ \dfrac{28}{13}:7=\dfrac{28}{13}:\dfrac{7}{1}=\dfrac{28}{13}\cdot \dfrac{1}{7}=\dfrac{28^{(7}}{13\cdot7}=\dfrac{4}{13}[/tex]
[tex]\it 9\cdot\dfrac{25}{2}=\dfrac{9\cdot25}{2}=\dfrac{225}{2}\\ \\ \dfrac{28}{13}:7=\dfrac{28}{13}:\dfrac{7}{1}=\dfrac{28}{13}\cdot \dfrac{1}{7}=\dfrac{28^{(7}}{13\cdot7}=\dfrac{4}{13}[/tex]