a)\(=-\dfrac{11}{18}+\dfrac{1}{3}=-\dfrac{11}{18}+\dfrac{6}{18}=-\dfrac{5}{18}\)
\(\dfrac{2}{9}\) - \(\dfrac{5}{6}\) + \(\dfrac{1}{3}\) = \(\dfrac{4}{18}\) - \(\dfrac{15}{18}\) + \(\dfrac{6}{18}\) = \(\dfrac{-5}{18}\)
b)\(=\dfrac{1}{2}+\dfrac{3}{2}.0,01.\left(-20\right).0,5=\dfrac{1}{2}-\dfrac{3}{20}=\dfrac{10}{20}-\dfrac{3}{20}=\dfrac{7}{20}\)