Explicație pas cu pas:
[tex] \frac{a}{3b} = \frac{15}{90} = > \frac{a}{15} = \frac{3b}{90} = m = > a = 15m \: \ \: \: \: \: \: \: \: b = 30m = > \frac{a}{b} = \frac{15m}{30m} = \frac{1}{2} [/tex]
[tex] \frac{2a + b}{3a - b} = \frac{2 \times 1 + 2}{3 \times 1 - 2} = \frac{4}{1} = 4[/tex]
