Răspuns:
[tex]\frac{3}{5}[/tex]
Explicație pas cu pas:
[tex]\frac{a}{b} = \frac{2}{3} => a=\frac{2b}{3} \\ \frac{3a-b}{a+b} = \frac{3x\frac{2b}{3} -b}{\frac{2b}{3}+b } =\frac{2b-b}{\frac{2b+3b}{3} } =\frac{b}{\frac{5b}{3} } =\frac{3b}{5b} =\frac{3}{5}[/tex]