Ta có :
\(72^{45}-72^{44}=72^{44}\left(72-1\right)=7^{44}.71\)
\(72^{44}-72^{43}=72^{43}\left(72-1\right)=72^{43}.71\)
Vì \(72^{44}.71>7^{43}.71\)
\(\Rightarrow72^{45}-72^{44}>72^{44}-72^{43}\)
72^45 - 72^44 = 72^44 ( 72 - 1 ) = 72^44 . 71
72^44 - 72^43 = 72^43 ( 72 - 1 ) = 72^43 . 71
Vì 44 > 43 nên 72^44 . 71 > 72^43 . 71 hay 72^45 - 72^44 > 72^44 - 72^43
Ta co
7245−7244=7244(72−1)=744.71
7244−7243=7243(72−1)=7243.71
Vì 7244.71>743.71