Question

? supra 3 + 13 supra 18 = 19 supra 18

Answer 1

x/3 + 13/18 = 19/18
6x+13=19
6x=6
x=1

Answer 2

$\it \frac{x}{3} + \frac{13}{18} = \frac{19}{18} = = > \\ \\ \it \frac{x}{3} = \frac{19}{18} - \frac{13}{18} = = > \\ \\ \it \frac{x}{3} = \frac{6}{18} = = > \\ \\ \it x = \frac{3 \cdot 6}{18} = = > \\ \\ \it x = \frac{18}{18} = = > \\ \\ \it \boxed{x = 1}$