$$ \dfrac{-5}{9} $$
It can be written
$$ \dfrac{-5}{9} = \dfrac{-5 \times 2}{9 \times 2} = \dfrac{-10}{18} $$
$$ \dfrac{-5}{9} = \dfrac{-5 \times 3}{9 \times 3} = \dfrac{-15}{27} $$
$$ \dfrac{-5}{9} = \dfrac{-5 \times 4}{9 \times 4} = \dfrac{-20}{36} $$
Therefore, $$ \dfrac{-10}{18} , \dfrac{-15}{27} $$ and $$ \dfrac{-20}{36} $$ are the rational numbers which are equivalent to the given rational number $$ \dfrac{-5}{9} $$.