Question

Imi trebuie si mie exercitiile 2 si 3.

Answer 1

x =lungimea drumului

1zi – 1/3*x……….restul2/3*x

2zi – ¼*2/3x ……….restul ¾*2/3*x

3zi – 18 km=ultimul rest

¾*2/3*x = 18

X = 18*12/6

X=36 km

Answer 2

1) a+b=20  c+d=30
    ac+ad+bc+bd=a(c+d)+b(c+d)=30a+30b=30(a+b)=30x20=600
2) I zi = x/3
    a IIa zi= 1/4(x-x/3)=1/4(2x/3)=x/6
    a IIIa zi=18   
adunam cele trei zile  x/3+x/6+18=x unde x este tot drumul
2x+x-6x=-108
-3x=-108 x=36   Izi=12  aIIazi=6   a IIIa zi=18