Problema 14
=>x:5=y:9=k (direct proportional)
x:5=k=>x=5k
y:9=k=>y=9k
70 sa fie impartit in x si in y, x + y=70
x+y=70=>5k+9k=70=>k(5+9)=70=>k*14=70=>k=70:14=>k=5
x=5k=5*5=25
y=9k=9*5=45
cele 2 parti cu 5 si 9 care nr. 70 poate fi impartit sunt 25 si 45.
Problema 8
a/5=b/6=c/13=k
a/5=5k
b/6=6k
c/13=13k
a+b+c=120
5k=6k=13k=120
24k=120
k=120/24
k=5
a=5*5=25
b=5*6=30
c=5*13=65
