Răspuns :
a+b+c=108
b=a+6
c=b+6⇒c=a+6+6⇒c=a+12
a+a+6+a+12=108
3a=108-18=90
a=90:3
a=30 km. in prima zi
b=30+6
b=36 km. in a doua zi
c=36+6
c=42 km. in a treia zi
V:30+36+42=108
R:in prima zi a parcurs 30 km
b=a+6
c=b+6⇒c=a+6+6⇒c=a+12
a+a+6+a+12=108
3a=108-18=90
a=90:3
a=30 km. in prima zi
b=30+6
b=36 km. in a doua zi
c=36+6
c=42 km. in a treia zi
V:30+36+42=108
R:in prima zi a parcurs 30 km