a) $ (\frac{2}{5}-\frac{1}{3})^{2}=(\frac{1}{15})^{2}=\frac{1}{225}$
b) $(1\frac{1}{2}-1.25)^{3}=(\frac{1}{4})^{3}=\frac{1}{64}$
c) $(\frac{1}{2}+\frac{1}{3})^{2}/(1\frac{1}{2})^{2}=(\frac{5}{6})^{2}/(\frac{3}{2})^{2}=\frac{25}{36}/\frac{9}{4}=\frac{25}{81}$
d) $2/(\frac{1}{2}-\frac{2}{3})^{3}=2/(\frac{-1}{216})=-432$