[tex]f) \\ \\ - \frac{8}{21} : ( - \frac{32}{63}) = - \frac{8}{21} : - \frac{32}{63} = - \frac{8}{21} \times \frac{63}{ - 32} = - \frac{8 \times 63}{21 \times - 32} = - \frac{504}{ - 672} = - ( - \frac{504}{672}) = - ( - \frac{3}{4}) = \frac{3}{4} [/tex]
[tex]g) \\ \\ - \frac{3}{8} : ( + \frac{16}{9}) = - \frac{3}{8} : \frac{16}{9} = - \frac{3}{8} \times \frac{9}{16} = - \frac{3 \times 9}{8 \times 16} = - \frac{27}{128} [/tex]
[tex]h) \\ \\ ( - \frac{4}{9}) : ( - \frac{16}{27}) = - \frac{4}{9} : - \frac{16}{27} = - \frac{4}{9} \times \frac{27}{ - 16} = - \frac{4 \times 27}{9 \times - 16} = - \frac{108}{ - 144} = - ( - \frac{108}{144}) = - ( - \frac{3}{4}) = \frac{3}{4} [/tex]
