= (2015 + 1) x 2017 - 2015 x ( 2017 + 1)
= 2015 x 2017 + 2017 x 1 - 2015 x 2017 + 2015 x 1
= 2017 x 1 - 2015 x 1 ( bớt 2 vế đi 2015 x 2017)
= 1 x ( 2017 - 2015)
= 1 x 2
= 2
= 4032
2016 x 2017 - 2015 x 2018 = 2016 x 2017 - 2015 x (2017+1) = 2016 x 2017 - 2015 x 2017 -2015 = 2017 x (2016-2015)-2015
=2017-2015=2
nhầm bằng 2 thôi bạn nhé , bỏ số 4032 đi nhé