Explicație pas cu pas:
[tex] \frac{x}{y} = \frac{5}{9} \\ \frac{4x + 2y}{3x + 5y} = \frac{ 4\frac{x}{y} + 2 \frac{y}{y} }{3 \frac{x}{y} + 5 \frac{y}{y} } = \\ \frac{4 \times \frac{5}{9} + 2}{3 \times \frac{4}{9} + 5 } = \frac{ \frac{20}{9} + 2 }{ \frac{4}{3} + 5} = \\ \frac{20 + 18}{9} \div \frac{4 + 15}{3} = \\ \frac{38}{9} \div \frac{19}{3} = \frac{38}{9} \times \frac{3}{19} = \frac{2}{3} [/tex]
