2
a+b+c=320
a=b-40
c=b*2
scriem toata ecuatia in functie de b si rezulta
b-40+b+b*2=320
4b=320+40
4b=360, b=360/4
b=90
a=90-40, a=50
c=90*2, c=180
proba
50+90+180=320
4
a+b=120
b=a+14
a+a+14=120
2a=120-14
2a=106
a=106/2
a=53kg in primul sac
in al 2-lea sac avem 53+14=67 kg
proba
53+67=120 kg
acum aflam cat costa 1 kg
480/120=4 lei kg
18kg*4 lei=72 lei
la problemele 3 si 4 nu mai stiu exact formulele cu cat si rest