Bài 6: 

a: \(2^{27}=8^9\)

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

b: Vì \(8^9< 9^9\)

nên \(2^{27}< 3^{18}\)

cảm ơn nha

99 + 1 = 100

9999 + 1 = 10000

999......9 + 1 = 1000.....0 ( dưới 1000....0 là " m chữ số 0 "

a: \(\left(\dfrac{1}{5}\right)\cdot\left(\dfrac{1}{5}\right)^{15}=\left(\dfrac{1}{5}\right)^{1+15}=\left(\dfrac{1}{5}\right)^{16}\)

b: \(\left(-10,2\right)^{10}:\left(-10,2\right)^3=\left(-10,2\right)^{10-3}=\left(-10,2\right)^7\)

c: \(\left[\left(-\dfrac{7}{9}\right)^7\right]^8=\left(-\dfrac{7}{9}\right)^{7\cdot8}=\left(-\dfrac{7}{9}\right)^{56}\)

Bài 1: 

a) \(4^8\cdot2^{20}=\left(2^2\right)^8\cdot2^{20}=2^{36}\)

 \(64^3\cdot4^5=\left(2^6\right)^3\cdot\left(2^2\right)^5=2^{18}\cdot2^{10}=2^{28}\)

\(y\cdot y^7=y^{1+7}=y^8\)

\(a^n\cdot a^2=a^{n+2}\)

Bài 1:

b) \(10^8:2^8=5^8\)

\(17^8:17^5=17^3\)

\(2^{25}:32^4=2^{25}:2^{20}=2^5\)

\(19^4:9^4=\left(\dfrac{19}{9}\right)^4\)

64

\(^{64^1=8^2=-8^2=4^3=2^6}\)

\(0,125^3.512\)

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

= \(\dfrac{1}{8^3}.8^3\)

=\(6^3\)

  (0,125)³. 512

=  (0,125)³. 8³

= (0,125.8)³

= 1³

= \(\left(\dfrac{1}{1^{ }}\right)^3\)

b: \(3^4\cdot3^5:\dfrac{1}{27}==3^9\cdot3^3=3^{12}\)

a) \(15^8\cdot2^4\)

\(=\left(15^2\right)^4\cdot2^4\)

\(=225^4\cdot2^4\)

\(=\left(225\cdot2\right)^4\)

\(=450^4\)

b) \(27^5:32^3\)

\(=\left(3^3\right)^5:\left(2^5\right)^3\)

\(=3^{15}:2^{15}\)

\(=\left(\dfrac{3}{2}\right)^{15}\)

a) = (5:2)^1234567 = (2,5)^1234567

b) = (9:3)^766676555 = 3^766676555

Tạ Quang Duy b là dấu chia mà