Răspuns :
[tex]6 \: kg \: ceapa \: ..... \: 18 \: lei \\ 3 \: kg \: ceapa \: ..... \: x \: lei[/tex]
[tex]x = \frac{3 \times 18}{6} = 3 \times 3 = 9 \: lei[/tex]
[tex]x = \frac{3 \times 18}{6} = 3 \times 3 = 9 \: lei[/tex]