Question

cum introduc 0.(3) • √21. , vreau calcul complet plus explicatie daca se poate​

Answer 1

 

0,(3) se inmulteste cu √21

Pentru a-l introduce pe 0,(3) sub radical il transformam in fractie

apoi il ridicam la patrat.

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$\displaystyle\bf\\0,3=\frac{~~3^{(3}}{9}=\frac{1}{3}\\\\\left(\frac{1}{3}\right)^2=\frac{1}{9}\\\\\implies~\sqrt\frac{1}{9}}=\frac{1}{3}\\\\\implies~0,(3)\cdot\sqrt{21}=\frac{1}{3}\cdot\sqrt{21}=\sqrt\frac{1}{9}}\cdot\sqrt{21}= \sqrt{\frac{1}{9}\cdot21}=\sqrt\frac{21}{9}=\boxed{\bf\sqrt\frac{7}{3}}\\\\Am~folosit~formula:~~~\sqrt{a}\cdot \sqrt{b}=\sqrt{a\cdot b}$