Răspuns:
[tex] \frac{a}{b} = \frac{3}{7} [/tex]
a+b=30
a=
[tex] \frac{3b}{7} [/tex]
[tex] \frac{3b}{7} + b = 30 \\ 10b = 210 \\ b = 21 [/tex]
10b=210
b=21
a= 22x3/7=9
a=9.
