484 (2,4) 485 (3,5,4)

484.
2)
$( \frac{3a^{2}}{2b})^{3} * \frac{16b^{3}}{21a^{4}} = \frac{27a^{6}}{8b^{3}}* \frac{16b^{3}}{21a^{4}}= \frac{9*3*16}{8*3*7} * a^{2}= \frac{18a^{2}}{7}$ ;
4)
abc² * $(\frac{ab}{cd} )^{2}= abc^{2} *\frac{a^{2}b^{2}}{c^{2}d^{2}}=\frac{a^{3}b^{3}}{d^{2}}$ .
485.
3)
$\frac{16x^2y}{7z} : \frac{10xy^3}{21z^2} = \frac{16x^2y}{7z} * \frac{21z^2}{10xy^3}= \frac{4,8xz}{y^2}$ ;
4)
$\frac{46d^3c}{15a} : \frac{23dc^2}{5a^3} = \frac{46d^3c}{15a} * \frac{5a^3}{23dc^2} = \frac{2d^2a^2}{3c} ;$
5)
$\frac{18m^3n^5}{7k} :9n^2= \frac{18m^3n^5}{7k*9n^2}= \frac{2m^3n^3}{7k}$