Laske.

a) [[$ 4\dfrac{3}{4} - 2\dfrac{1}{2} + 3\dfrac{3}{8} $]] =

b) [[$ -\dfrac{5}{6} - 2\dfrac{3}{4} $]] =

c) [[$ \dfrac{7}{8} - 5\dfrac{4}{7} $]] =