fie x traseul de parcurs
prima zi x-3x/7= 7x-3x/7=4x/7.
a doua zi 4x/7 - 3/5din4x/7=8x/35.
3x/7 + 12x/35+32= x
15x+12x+1120=35x
27x+1120=35x
1120=35x-27x
1120=8x
x=1120:8
x= 140km.(lungimea traseului )
b) prima zi = 3·140/7 = 60km.
c) a doua zi = 140-60 = 80km au mai ramas
= 3/5·80 = 48km.