+Ta co : 7245-744=721=72
7244-7243=721=72
Do 72=72
Vay 7245-7244=7244-7243
\(72^{45}-72^{44}=72^{44}\left(72-1\right)=72^{44}.71\)
\(72^{44}-72^{43}=72^{43}\left(72-1\right)=72^{43}.71\)
\(Vì\) \(72^{44}.71>72^{43}.71\)
\(\Rightarrow72^{45}-72^{44}>72^{44}-72^{43}\)
7245 - 7244 = 7245 - 44 = 721
7244 - 7243 = 7244 - 43 = 721
Vì 721 = 721 nên 7245 - 7244 = 7244 - 7243
Học tốt!!!