a) \(125^5=\left(5^3\right)^5=5^{3\cdot5}=5^{15}\)
\(25^7=\left(5^2\right)^7=5^{2\cdot7}=5^{14}\)
\(5^{15}>5^{14}\Rightarrow125^5>25^7\)
b) \(3^{54}=\left(3^2\right)^{27}\)
\(2^{81}=\left(2^3\right)^{27}\)
\(3^2>2^3\Rightarrow3^{54}>2^{81}\)
d)
5^40 = ( 5^4)^10 = 625^10
mà 625^10 > 620^10 => 5^40 > 620^10
vậy ............
c)
10^30 = (10^3)^10 = 1000^10
2^100 = (2^10)^10 = 1024^10
mà 1000^10 < 1024^10 => 10^30 < 2^100
k mik nha!