Laske.

a) [[$ \dfrac{1}{x} + \dfrac{2}{x} $]] =

b) [[$ \dfrac{3}{a} + \dfrac{5}{a} $]] =

c) [[$ \dfrac{8}{b} - \dfrac{3}{b} $]] =

d) [[$ \dfrac{12}{2y} - \dfrac{10}{2y} $]] =