a si b cele doua numere
a+b=70
a/5=b/9 deci a=5b/9
5b/9 + b=70 aducem la acelasi numitor comun
5b+9b=630
14b=630
b=630/14
b=45
a=70-b=70-45=25
Verificare
25/5=45/9
La14pct a
a/8=b/12 deci a/b=8/12=2/3
impartim numaratorul si numitorul la b
=(5a/b+3)/3=(5x2/3+3)/3=(10+9)/3/3=19/3:3=19/3x1/3=19/9
