Răspuns:
[tex]x + y = 231 \\ x = 75\%y = \frac{75y}{100} = \frac{3y}{4} \\ \frac{3y}{4} + y = 231 \\ \frac{3y + 4y}{4} = 231 \\ \frac{7y}{4} = 231 \\ 7y = 924 \\ y = 132 \\ x = \frac{3}{4} \times 132 = 99[/tex]
