Bài 6: 

a: \(2^{27}=8^9\)

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

b: Vì \(8^9< 9^9\)

nên \(2^{27}< 3^{18}\)

a) 5³ . 5² . 5 

= 5⁵ . 5 

= 5⁵ . 5¹

= 5⁶

b) 6⁹ : 6⁴ 

= 6⁵

c) 4 . 8 . 16 . 32 

= 2² . 2³ . 2⁴ . 2⁵

= 2⁵ . 2⁴ . 2⁵

= 2⁹ . 2⁵

= 2¹⁴ 

254 . 28 = 58 . 28 = 108

158 . 94 = 158 . 38 = 458

108 : 28 = (10:2)8 = 58

272 : 253 = (33)2 : (52)3 

= 33.2 : 52.3

 = 36 :  5 6 = 3 5 6

\(0,125^3.512\)

=\(\left(\dfrac{1}{8}\right)^3.8^3\)

= \(\dfrac{1}{8^3}.8^3\)

=\(6^3\)

  (0,125)³. 512

=  (0,125)³. 8³

= (0,125.8)³

= 1³

= \(\left(\dfrac{1}{1^{ }}\right)^3\)

`a, = 5^3 xx 3^3 = 15^3`

`b, = 12^3 xx 4^3 = 48^3`

`c, = 625^3 xx 8^3 = 5000^3`

`d, = 625 ^3 xx 125^3 = 78125^3`

`e, = 5^20 : 5^14 = 5^6`

1,\(125\cdot27=5^3\cdot3^3=\left(5\cdot3\right)^3=15^3\)

2, \(12^3\cdot64=12^3\cdot4^3=\left(12\cdot4\right)^3=48^3\)

3, \(25^6\cdot8^3=\left(5^2\right)^6\cdot\left(2^3\right)^3=5^8\cdot2^9\)

4, \(25^6\cdot125^3=\left(5^2\right)^3\cdot\left(5^3\right)^3=5^6\cdot5^9=5^{15}\)

5,\(625^5:25^7=\left(5^4\right)^5:\left(5^2\right)^7=5^{20}:5^{14}=5^6\)

25⁴ . 2⁸ = (5²)⁴ . 2⁸ = 5^2.4 . 2⁸ = 5⁸ . 2⁸ = (5 . 2)⁸ = 10⁸

25⁴.2⁸=(5²)⁴.2⁸=5⁸.2⁸=(5.2)⁸=10⁸=100000000