Question

(+3/7):(+21/49) calcule

Answer 1

Lembrete:

$\mathsf{\dfrac{a}{b}\div \dfrac{c}{d}=\dfrac{a}{b}\cdot \dfrac{d}{c}}$
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Resolvendo:

$\mathsf{\dfrac{3}{7}\div \dfrac{21}{49}}\\\\\\\mathsf{\dfrac{3}{7}\cdot \dfrac{49}{21}}\\\\\\\mathsf{\dfrac{3\cdot 49}{7\cdot 21}}\\\\\\\mathsf{\dfrac{3\cdot 7\cdot 7}{7\cdot 3\cdot 7}}\\\\\\\boxed{\boxed{\mathsf{1}}}\: \: \checkmark$