Bài 6: 

a: \(2^{27}=8^9\)

\(3^{18}=9^9\)

b: Vì \(8^9< 9^9\)

nên \(2^{27}< 3^{18}\)

A = 3 2 . 5 2 - 4 2 = 7 = 126 = 6 3

A = 2 2 . 5 2 - 3 2 - 10 =   81   =   3 4   =   9 2  

D = 4 3 + 6 3 + 7 3 + 2 = 625 = 25 2

c) \(\left(\dfrac{5}{4}\right)^4:\left(\dfrac{15}{2}\right)^4=\left(\dfrac{5}{4}:\dfrac{15}{2}\right)^4=\left(\dfrac{1}{6}\right)^4\)

d) \(10^4:16=10^4:2^4=\left(10:2\right)^4=5^4\)

e) \(\left(-2\right)^3.125=\left(-2\right)^3.5^3=\left(-2.5\right)^3=-10^3\)

f) \(64^3:\left(-2\right)^9=64^3:\left(-8\right)^3=\left(64:-8\right)^3=-8^3\)

C = 5 . 4 3 + 2 4 . 5 = 400 = 20 2

B = 2 3 . 4 2 + 3 2 . 3 2 - 40 =   169   =   13 3

C = 11 . 2 4 + 6 2 . 19 + 40 = 900 = 30 2

B = 3 3 . 5 2 + 2 2 . 3 2 + 18 = 279 = 27 3 = 3 6 = 9 3