Notam cu „ a " traseul parcurs ! In prima zii : [tex] \frac{25}{100} *x = \frac{x}{4} [/tex]. . A doua zii : [tex] \frac{35}{100} *x = \frac{7x}{20} [/tex]. . A treia zii : 48 km !
[tex]x= \frac{x}{4} + \frac{7x}{20} +48 =\ \textgreater \ 20x=5x+7x+960 \\ =\ \textgreater \ 8x=960=\ \textgreater \ x=120km[/tex]