2017 × 2018 - 2017 × 1018 - 1000 × 2016 =
= 2017 × ( 2018 - 1018 ) - 1000 × 2016 =
= 2017 × 1000 - 1000 × 2016 =
= 1000 × ( 2017 - 2016 ) =
= 1 000 × 1 =
= 1 000
