Ta có:
2016 x 2016
= (2015 + 1) x 2016
= 2015 x 2016 + 2016
2015 x 2017
= 2015 x (2016 + 1)
= 2015 x 2016 + 2015
Vì 2016 > 2015
=> 2016 x 2016 > 2015 x 2017
Ta có:
2016 x 2016
= (2015 + 1) x 2016
= 2015 x 2016 + 2016
2015 x 2017
= 2015 x (2016 + 1)
= 2015 x 2016 + 2015
Vì 2016 > 2015
=> 2016 x 2016 > 2015 x 2017