Răspuns:
x/14= 5/ (1/5+1/2)
x(²⁾1/5+⁵⁾1/2)=14·5
x(2/10+5/10)=70
7x/10=70
7x=70·10=>x=700/7=>x=100
[tex]\it \dfrac{x}{14}=\dfrac{5}{\dfrac{1}{5}+\dfrac{1}{2}} \Rightarrow x= \dfrac{5\cdot14}{\dfrac{1}{5}+\dfrac{1}{2}}=\dfrac{5\cdot14}{\dfrac{7}{10}}=70:\dfrac{7}{10}=70\cdot\dfrac{10}{7}=\dfrac{700}{7}=100[/tex]
