[1\frac{3}{8}:3\frac{2}{3}+(1\frac{1}{2})^2]*\frac{3}{7}=
=[\frac{11}{8}:\frac{11}{3}+(\frac{3}{2})^2]*\frac{3}{7}=
=[\frac{11}{8}*\frac{3}{11}+\frac{9}{4}]*\frac{3}{7}=
=[\frac{3}{8}+\frac{18}{8}]*\frac{3}{7}=
=\frac{21}{8}*\frac{3}{7}=\frac{9}{8}=1\frac{1}{8}