Answer:
[tex]x + 12 \frac{3}{4} = 16 \frac{4}{9} \\ \\ x + \frac{51}{4} = \frac{148}{9} \\ \\ x = \frac{148}{9} - \frac{51}{4} \\ \\ x = \frac{592}{36} - \frac{459}{36} \\ \\ x = \frac{133}{36} \\ \\ \\ x = 3 \frac{25}{36} [/tex]
So; the number
[tex]3 \frac{25}{36} [/tex]