a) \(0,75+\dfrac{-1}{3}-\dfrac{5}{18}=\dfrac{3}{4}+\dfrac{-1}{3}-\dfrac{5}{18}=\dfrac{5}{12}-\dfrac{5}{18}=\dfrac{5}{36}\)
b) \(7\dfrac{3}{5}-\left(2\dfrac{5}{7}+5\dfrac{3}{5}\right)=\dfrac{38}{5}-\left(\dfrac{19}{7}+\dfrac{28}{5}\right)=\dfrac{38}{5}-\dfrac{19}{7}+\dfrac{28}{5}=\left(\dfrac{38}{5}-\dfrac{28}{5}\right)+\dfrac{19}{7}=2+\dfrac{19}{7}=\dfrac{33}{7}\)
c) \(\dfrac{4}{15}\cdot\dfrac{1}{3}\cdot\dfrac{15}{20}=\dfrac{4}{15}\cdot\dfrac{1}{3}\cdot\dfrac{3}{4}=\dfrac{4}{45}\cdot\dfrac{3}{4}=\dfrac{12}{180}=\dfrac{1}{15}\)
d) \(\dfrac{-1}{9}\cdot\dfrac{15}{22}:\dfrac{-25}{9}=\dfrac{-5}{66}:\dfrac{-25}{9}=\dfrac{-5}{66}\cdot\dfrac{-9}{25}=\dfrac{3}{110}\)
