Respuesta :

Solve for x

[tex]\begin{gathered} \frac{5}{7}=\frac{x}{21} \\ 5\cdot21=7\cdot x \\ 105=7x \end{gathered}[/tex]

Divide both sides by 7

[tex]\begin{gathered} \frac{105}{7}=\frac{7x}{7} \\ x=15 \end{gathered}[/tex]

Answer: x = 15