Question

Answer 1

7: \(=\left(-\dfrac{1}{2}-\dfrac{1}{9}-\dfrac{7}{18}\right)+\left(\dfrac{3}{5}+\dfrac{4}{35}+\dfrac{2}{7}\right)+\dfrac{1}{127}=\dfrac{1}{127}\)

8: \(=\dfrac{17}{23}\cdot\dfrac{23}{17}\cdot\dfrac{1}{2}\cdot\dfrac{3}{4}\cdot\left(-80\right)=\dfrac{\left(-80\right)}{8}\cdot3=-30\)

9: \(=\dfrac{5}{11}\left(\dfrac{18}{29}-\dfrac{8}{29}+\dfrac{19}{29}\right)=\dfrac{5}{11}\cdot1=\dfrac{5}{11}\)