Resposta:

[tex]12\%x - 5 = 2 \times ( \frac{2\%x}{2} ) \\ \frac{12}{100} x - 5 = \frac{2}{100}x \\ \frac{12}{100}x - \frac{2}{100}x = 5 \\ \frac{10}{100}x = 5 \\ 10x = 500 \\ x = 50[/tex]