Explicație pas cu pas:
[tex] \frac{x}{3} + (x - \frac{x}{3} ) \times \frac{2}{3} + 12 = x \\ \frac{x}{3} + (\frac{3x - x}{3} ) \times \frac{2}{3} + 12 = x \\ \frac{x}{3} + \frac{4x}{9 } + 12 = 3x + 4x + 108 = 9x \\ 7x - 9x = - 108 \\ x = \frac{108}{2} = 54[/tex]
