Question

$2003^{2} - 1997^{2}$

Answer 1

$2003^2-1997^2=(2003-1997)(2003+1997)=6*4000=24000$

Answer 2

1 способ:
(2003-1997)*(2003+1997)
6*4000=24000
2 способ:
(2003*2003)-(1997*1997)
4012009-3988009=24000