[tex]\displaystyle 9 \ = \ \frac{1}{10} \ of \ x \\ \\ \\ 9 = \frac{1}{10} \cdot x \\ \\ \\ x \cdot \frac{1}{10}=9 \\ \\ \\ x=9: \frac{1}{10} \\ \\ \\ x= 9 \cdot \frac{10}{1} \\ \\ \\ \boxed{x=90} \\ \\ \\ \boxed{\boxed{\text{The answer is x=90}}}[/tex]