Question

va roggg
dau inimioara

Answer 1

n = lungimea drumului,

prima etapa a parcurs n/3, a ramas de parcurs n-n/3=2n/3

a doua etapa a parcurs (2n/3)*(1/3)=2n/9

lungimea totala n=(n/3)+(2n/9)+4, numitor comun 9,

9n=3n+2n+36, 4n=36, n=36/4=9 km

Answer 2

Notez cu a lungimea drumului a

a - a / 3 - ( a - a / 3 ) / 3 = 4

a - a / 3 - ( 3 a / 3 - a / 3 ) × 1 / 3 = 4

a - a / 3 - 2 a / 9 = 4

9 a - 3 a - 2 a = 9 × 4

4 a = 36

a = 36 : 4

a = 9 km → lungimea drumului