[tex]x - lungimea \: traseului[/tex]
[tex] \frac{3}{5} \times x + \frac{20}{100} \times (x - \frac{3}{5} \times x) + 56 = x[/tex]
[tex] \frac{3x}{5} + \frac{1}{5} \times (x - \frac{3x}{5} ) + 56 = x[/tex]
[tex] \frac{3x}{5} + \frac{x}{5} - \frac{3x}{25} + 56 = x \: | \times 25[/tex]
[tex]15x + 5x - 3x + 1400 = 25x[/tex]
[tex]15x + 5x - 3x - 25x = - 1400[/tex]
[tex] - 8x = - 1400 \: | \div ( - 8)[/tex]
[tex]x = 175 \: km[/tex]