a) Ta có: \(\left(\dfrac{1}{243}\right)^6=\left(\dfrac{1}{3}\right)^{5\cdot6}=\left(\dfrac{1}{3}\right)^{30}\)

\(\Leftrightarrow\left(\dfrac{1}{3}\right)^{28}>\left(\dfrac{1}{243}\right)^6\)

\(\Leftrightarrow\left(\dfrac{1}{3^4}\right)^7>\left(\dfrac{1}{243}\right)^6\)

\(\Leftrightarrow\left(\dfrac{1}{81}\right)^7>\left(\dfrac{1}{243}\right)^6\)

mà \(\left(\dfrac{1}{80}\right)^7>\left(\dfrac{1}{81}\right)^7\)

nên \(\left(\dfrac{1}{80}\right)^7>\left(\dfrac{1}{243}\right)^6\)

\(\left(\dfrac{3}{8}\right)^5\&\left(\dfrac{5}{243}\right)^3\)
\(\left(\dfrac{3}{8}\right)^5=\left(\dfrac{90}{240}\right)^5=\dfrac{90^5}{240^5}\)

\(\left(\dfrac{5}{243}\right)^3=\dfrac{5^3}{243^3}\)

\(=>\dfrac{90^5}{240^5}>\dfrac{5^3}{243^3}\)

\(=>\left(\dfrac{3}{8}\right)^5>\left(\dfrac{5}{243}\right)^3\)

\(\left(\dfrac{1}{80}\right)^7\&\left(\dfrac{1}{243}\right)^6\)

\(\dfrac{1}{80}>\dfrac{1}{81}=\dfrac{1}{3^4}\)

\(=>\left(\dfrac{1}{80}\right)^7>\left(\dfrac{1}{3^4}\right)^7=\dfrac{1}{3^{7.4}}=\dfrac{1}{3^{28}}>\dfrac{1}{3^{30}}\)

\(=\dfrac{1}{\left(3^5\right)^6}=\left(\dfrac{1}{243}\right)^6\)

\(=>\left(\dfrac{1}{80}\right)^7>\left(\dfrac{1}{243}\right)^6\)

(3/8)⁵= 3⁵/(2³)⁵=243/2¹⁵>243/3¹⁵>125/3¹⁵=5³/(3⁵)³=(5/3⁵)³=(5/243)³

suy ra (3/8)⁵>(5/243)³

Ta có : 

\(\frac{1}{243^9}=\frac{1}{\left(81.3\right)^9}=\frac{1}{81^9.27^3}>\frac{1}{81^9.81^3}=\frac{1}{81^{11}}>\frac{1}{8^{12}}>\frac{1}{8^{13}}\)

\(\Rightarrow\frac{1}{243^9}>\frac{1}{8^{13}}\)

3A=3+3^2+3^3+...+3^100

2A=3A-A=(3+3^2+3^3+....+3^1000-(1+3+3^2+....+3^99) = 3^100-1

=>2A+1 = 3^100 = (3^5)^20 = 243^20

Vậy 2A+1 = 243^20

k mk nha

Ta có :

\(\frac{1}{243^9}=\frac{1}{\left(81.3\right)^9}=\frac{1}{81^9.27^3}>\frac{1}{81^9.81^3}=\frac{1}{81^{11}}>\frac{1}{8^{12}}>\frac{1}{8^{13}}\)

\(\Rightarrow\frac{1}{243^9}>\frac{1}{83^{13}}\)

mình chắc chắn luôn

-https://olm.vn/hoi-dap/detail/77727486175.html

a: \(A=8^2\cdot32^4=2^6\cdot2^{20}=2^{26}\)

b: \(B=27^3\cdot9^4\cdot243=3^9\cdot3^8\cdot3^5=3^{22}\)

sai đề rồi

\(\Leftrightarrow3^x\cdot3=243\)

hay x=4

 Ta có :C= 2181-729+243.81-27

=2052+19683-27

C=21108

D=\(3^2.9^2.243+18.243.324.243\)

=9.81.243+18.243.324.243

=177147+344373768

=344550915

Ta có : C:D=21108:344550915=0,00006

a)3^x+1=9^x

3^x+1=3.3^x

3^x+1=3^x+1

=>x thuộc TH Z

b)2^3.x+2=4^x+5

2^3x+2=2^2.(x+5)

2^3x+2=2^2x+10

2^3x=2^2x+8

3x-2x=8

=>x=8

c)3^2x-1=243

3^2x=243.3

3^2x=729

3^2x=3^6

=>2x=6

x=6:2=3

chúc bạn học tốt nha

thank you

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