Respuesta :

[tex]\begin{gathered} y=\frac{k}{x} \\ \text{when y = 18, x = 7} \\ k\text{ = xy = 18}\times7\text{ = 126} \\ \text{Also, using} \\ y=\frac{k}{x} \\ y\text{ =}\frac{126}{3}\text{ = 42} \end{gathered}[/tex]