1) Equivalent ratios share the same constant of proportion, simplifying it we have:
[tex]\begin{gathered} \frac{10}{20}=\frac{1}{2} \\ \frac{1}{2} \\ \frac{9}{3}=3 \\ \frac{6}{2}=3 \end{gathered}[/tex]2) SO yes, these ratios 10/20 and 1/2 are equivalent and 9/3 and 6/2 are equivalent between them.