$b)$ $So$ $sánh:$ $222³³³$ $và$ $333²²²$
$Ta$ $có:$
$222³³³ = (222³)¹¹¹ = (2³.111³)¹¹¹ = (8.111³)¹¹¹$
$333²²² = (333²)¹¹¹ = (3².111²)¹¹¹ = (9.111²)¹¹¹$
$Vì 8.111³/9.111² = 8.111/9 > 1$
$⇒ 8.111³ > 9.111²$
$⇒ (8.111³)¹¹¹ > (9.111²)¹¹¹$
$⇒ 222³³³ > 333²²².$