Respuesta :

loneguy

[tex]\dfrac 57 \cdot x = \dfrac 5{21}\\\\\\\implies \dfrac x 7 = \dfrac 1{21}\\\\\\\implies 21x = 7\\\\\implies x = \dfrac{7}{21}\\\\\\ \text{Hence}~\dfrac 57 ~ \text{of}~~ \dfrac{7}{21}~ ~\text{is}~ \dfrac{5}{21}[/tex]