2/5:(3/7:4/3)=
=2/5:(3/7×3/4)=
=2/5:9/28=
=2/5×28/9=56/45
[tex]\frac{2}{5}:(\frac{3}{7}:\frac{4}{3})\\\\=\frac{2}{5}:(\frac{3}{7}*\frac{3}{4} )\\\\=\frac{2}{5}:\frac{9}{28} \\\\=\frac{2}{5}*\frac{28}{9}\\\\=\frac{56}{45}[/tex]
