Răspuns:
[tex]\red{ b : 2 : a = 20^{-1}}[/tex]
Explicație pas cu pas:
[tex]a:b:2 = 5 \Rightarrow \dfrac{a}{b} : 2 = 5 \Rightarrow \dfrac{a}{b} \cdot \dfrac{1}{2} = 5[/tex]
[tex]\dfrac{a}{b} \cdot \dfrac{1}{2} = 5 \Rightarrow \dfrac{a}{2b} = 5 \Rightarrow a = 10b[/tex]
[tex]b:2:a = b:2:10b = \dfrac{b}{2} :10b[/tex]
[tex]\dfrac{b}{2} \cdot \dfrac{1}{10b} = \dfrac{b}{20b}= \dfrac{1}{20} = 20^{-1}[/tex]
