Solution

Additive inverse of $$\dfrac ab$$ is $$-\dfrac ab$$, since $$\dfrac ab + \left(-\dfrac ab\right) = 0$$
In the same manner:
(i)
Additive inverse of $$\dfrac28$$ is $$-\dfrac{2}{8}$$

(ii)
Additive inverse of $$\dfrac{-5}9$$ is $$\dfrac{5}{9}$$

(iii)
Additive inverse of $$\dfrac{-6}{-5}$$ is $$\dfrac{-6}{5}$$

(iv)
Additive inverse of $$\dfrac2{-9}$$ is $$\dfrac{2}{9}$$

(v)
Additive inverse of $$\dfrac{19}{-6}$$ is $$\dfrac{19}{6}$$