Notam x=lungimea drumului.
20% x+ 30% (x- 20% x)+560=x
[tex] \frac{20*x}{100} + \frac{30}{100} *\frac{80*x}{100}+560=x
[/tex]
[tex] \frac{x}{5}+ \frac{3}{10}* \frac{4*x}{5} +560=x[/tex]
[tex] \frac{10*x+12*x+50*560}{50} =x[/tex]
22*x+28000=50*x
28000=28*x
x=1000
Coronita?