5/9:(7/9+11/18) (amplificam prima fractie din paranteza cu 2)
5/9:(14/18+11/18)=5/9:25/18 (scriem prima fractie cu a doua inversata)
5/9×18/25(simplificam 9 si 18 prin 9 si 5 cu 25 prin 5)
1/1×2/5=2/5
Raspunsul: 2/5
[tex]\displaystyle\bf\\\frac{5}{9}:\left(\frac{^{2)}7}{~~9}+\frac{11}{18} \right)=\\\\\\=\frac{5}{9}:\left(\frac{14}{18}+\frac{11}{18} \right)=\\\\\\=\frac{5}{9}:\left(\frac{14}{18}+\frac{11}{18} \right)=\\\\\\=\frac{5}{9}:\frac{14+11}{18}=\\\\\\=\frac{5}{9}:\frac{25}{18}=\\\\\\=\frac{5}{9}\times\frac{18}{25}=\\\\\\=\frac{5\times18}{9\times25}=\boxed{\bf\frac{2}{5}}[/tex]
