2 câu trả lời
$\text{ Ta có : }$
`3^{54} = ( 3^2 )^{27} = 9^{27}`
`2^{81} = ( 2^3 )^{27} = 8^{27}`
$Vì$ `9 > 8` $nên$ `9^{27} > 8^{27}` $hay$ `3^{54} > 2^{81}`
$Vậy$ `3^{54} > 2^{81}`
$3^{54}$=$3^{2.27}$= $(3^2)^{27}$= $9^{27}$
$2^{81}$=$2^{3.27}$= $(2^3)^{27}$= $8^{27}$
Vì $9^{27}$> $8^{27}$
⇒$3^{54}$>$2^{81}$
Vậy $3^{54}$>$2^{81}$