Răspuns: [tex]\bf \red{\underline{~x=15~}}[/tex]
Explicație pas cu pas:
{20, 4} i.p. {3; x}
[tex]\bf \dfrac{20}{\dfrac{1}{3}}= \dfrac{4}{\dfrac{1}{x}}\Rightarrow[/tex]
[tex]\bf 20\cdot\dfrac{3}{1}= 4\cdot\dfrac{x}{1}\Rightarrow 60=4x\Rightarrow[/tex]
[tex]\bf x=60:4\Rightarrow \red{\underline{~x=15~}}[/tex]
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