Verified answer

[tex]\large\sf{} \dfrac{1}{2} = \dfrac{x}{9} \\ \\ \large\sf{}1 \times 9 = 2x \\ \\\large\sf{}9 = 2x \\\large\sf{}2x = 9 \\ \\ \large\sf{}x = \dfrac{9}{2} \\ \\ {\large\boxed{\boxed{  { \large \sf x = 4,5}}}}[/tex]

[tex]{\large\boxed{\boxed{  { \large \sf Bons~Estudos }}}}[/tex]