Sagot :
[tex]If\ x\ and\ y\ are\ directly\ proportional\ then\ \frac{y}{x}\ is\ constans\\---------------------------\\\\\frac{2}{3}=\frac{y}{9}\\\\cross\ multiply\\\\3y=2\times9\\\\3y=18\ \ \ \ |divide\ both\ sides\ by\ 3\\\\y=6[/tex]