Un calator parcurge in prima zi jumatate din lungimea drumului si inca un km a doua zi ,o treime din drum si inca un km iar in a treia zii ultimii 3 km.
Cati km are drumul?
prima zi⇒y/2+1km; a doua zi⇒y/3+1km; a treia zi⇒ultimii 3 km; ⇒y-y/2+1km-y/3+1km=3⇒se reduce 1km cu 1km; ⇒y-y/2-y/3=3 ⇒6y/6-3y/6-2y/6=3 ⇒3y/6-2y/6=3 ⇒y/6=3⇒y=6·3⇒y=18[km-are drumul];
