\(=\left(\dfrac{15}{2021}+\dfrac{16}{2022}-\dfrac{115}{2023}\right)\cdot\dfrac{3-2-1}{6}=0\)
\(\left(\dfrac{15}{2021}+\dfrac{16}{2022}-\dfrac{115}{2023}\right)\cdot\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{6}\right)=\left(\dfrac{15}{2021}+\dfrac{8}{1011}-\dfrac{115}{2023}\right)\cdot\left(\dfrac{3}{6}-\dfrac{2}{6}-\dfrac{1}{6}\right)=\left(\dfrac{15}{2021}+\dfrac{8}{1011}-\dfrac{115}{2023}\right)\cdot0=0\)
(15/2021+16/2022-115/2023).(1/2-1/3-1/6)
=(15/2021+16/2022-115/2023).(1/6-1/6)
=(15/2021+16/2022-115/2023).0
=0