a) \({2^m}{.2^n}=\underbrace {2.2 \ldots .2}_{m{\rm{ }}}{\rm{ }}.\underbrace {2.2 \ldots .2}_{n{\rm{ }}}{\rm{ }}\) = 2^m+n

b) \({3^m}:{3^n}=(\underbrace {3.3 \ldots .3}_{m{\rm{ }}}{\rm{ }}):(\underbrace {3.3 \ldots .3}_{n{\rm{ }}}{\rm{ }})\) = 3^m-n  với \(m \ge n\)

a) `7^4 .7^5 .7^6 = 7^(4+5+6)=7^(15)`

b) `(54:3^7) .324 =( 2.3^3 : 3^7).2^2 x3^4`

`=(2: 3^4).3^4 .2^2`

`= 2.2^2=2^3`

c) `[(8+2^2).10^100] : (10^0 .10^94)`

`=(12 . 10^100) : 10^94`

`=12 . (10^100 : 10^94)`

`=12 . 10^6`

d) `a^9 :a^9 = a^(9-9)=a^0`

a)  \(\frac{6}{5}.{\left( {1,2} \right)^8} = 1,2.{(1,2)^8} = {(1,2)^{1 + 8}} = {(1,2)^9}\)

b) \({\left( {\frac{{ - 4}}{9}} \right)^7}:\frac{{16}}{{81}} = {\left( {\frac{{ - 4}}{9}} \right)^7}:{\left( {\frac{{ - 4}}{9}} \right)^2} = {\left( {\frac{{ - 4}}{9}} \right)^{7 - 2}} = {\left( {\frac{{ - 4}}{9}} \right)^5}\)

3⁴ . 3⁵ = 3⁴⁺⁵ = 3⁹

\(34\cdot35\)   

\(=1190\)    

\(=1190^1\)

Chọn B

B 

=> \(^{2^8}\) = 256

B

a) 3.3^4.3^5 = 3^10

b) 7^3 : 7^2 : 7 = 7^1

c) (x^4)^3 = x^12

a) \(3^3 : 3^2\)=\(3^{3-2}=3^1\)

b) \(5^{4} : 5^{2}\)=\(5^{4-2}=5^2\)

c) \(8^{3} . 8^{2}\)=\(8^{3+2}=8^5\)

d) Cách 1:

\(5^{4} . 5^{3}: 5^{2}=5^{4+3}:5^2=5^7:5^2=5^{7-2}=5^5\)

Cách 2: 

\(5^{4} . 5^{3}: 5^{2}=5^{4+3-2}=5^5\)

Câu 9: C

Câu 10: C