Răspuns :
[tex]\it Inversul\ \ lui\ \ \dfrac{a}{b}\ este\ \ \dfrac{b}{a} \\ \\ 7\dfrac{1}{7}=\dfrac{50}{7} \Rightarrow \ inversul\ \ cerut\ \ este\ \ \dfrac{7}{50}[/tex]
[tex]\it Inversul\ \ lui\ \ \dfrac{a}{b}\ este\ \ \dfrac{b}{a} \\ \\ 7\dfrac{1}{7}=\dfrac{50}{7} \Rightarrow \ inversul\ \ cerut\ \ este\ \ \dfrac{7}{50}[/tex]