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30 tháng 9 2021

\(\left(\dfrac{4}{9}\right)^{x+1}=\left(\dfrac{8}{27}\right)^6\)

\(\Leftrightarrow\left(\dfrac{2}{3}\right)^{2x+2}=\left(\dfrac{2}{3}\right)^{18}\)

\(\Leftrightarrow2x+2=18\Leftrightarrow2x=16\Leftrightarrow x=8\)

 

19 tháng 2 2018

a)\(\frac{x}{5}=\frac{2}{5}\)

\(\Leftrightarrow x=\frac{2\times5}{5}=2\)

Vậy .............

b) \(\frac{3}{8}=\frac{6}{x}\)

\(\Leftrightarrow x=\frac{8\times6}{3}=16\)

Vậy ................

c) \(\frac{1}{9}=\frac{x}{27}\)

\(\Leftrightarrow x=\frac{1\times27}{9}=3\)

Vậy ................

d) \(\frac{4}{x}=\frac{8}{6}\)

\(\Leftrightarrow x=\frac{4\times6}{8}=3\)

Vậy ............

e) \(\frac{3}{x-5}=\frac{-4}{x+2}\)

\(\Leftrightarrow3\left(x+2\right)=-4\left(x-5\right)\)

\(\Leftrightarrow3x+6=-4x+20\)

\(\Leftrightarrow3x+4x=20-6\)

\(\Leftrightarrow7x=14\)

\(\Leftrightarrow x=2\)

Vậy .............

f) \(\frac{x}{-2}=\frac{-8}{x}\)

\(\Leftrightarrow x^2=16\)

\(\Leftrightarrow x=\pm4\)

Vậy ...............

19 tháng 2 2018

\(\frac{x}{5}=\frac{2}{5}\Rightarrow x=\frac{2\times5}{5}=2\)

\(\frac{1}{9}=\frac{x}{27}\Rightarrow x=\frac{1\times27}{9}=3\)

\(\frac{4}{x}=\frac{8}{6}\Rightarrow x=\frac{8\times6}{8}=6\)

\(\frac{3}{x-5}=\frac{-4}{x+2}\)

\(\Rightarrow3.\left(x+2\right)=-4.\left(x-5\right)\)

\(\Rightarrow3x+6=-4x+20\)

\(\Rightarrow3x+4x=20-6\)

\(\Rightarrow7x=14\)

\(\Rightarrow x=2\)

3 tháng 9 2020

Trả lời :

\(\left(\frac{4}{9}\right)^{x+1}=\left(\frac{8}{27}\right)^6\)

\(\Rightarrow\left[\left(\frac{2}{3}\right)^2\right]^{x+1}=\left[\left(\frac{2}{3}\right)^3\right]^6\)

\(\Rightarrow\left(\frac{2}{3}\right)^{2x+2}=\left(\frac{2}{3}\right)^{18}\)

\(\Rightarrow2x+2=18\)

\(\Rightarrow2x=16\)

\(\Rightarrow x=8\)

\(\left(\frac{4}{9}\right)^{x+1}=\left(\frac{8}{27}\right)^6=>\left[\left(\frac{2}{3}\right)^2\right]^{x+1}=\left[\left(\frac{2}{3}\right)^3\right]^6\)

\(\left(\frac{2}{3}\right)^{2.\left(x+1\right)}=\left(\frac{2}{3}\right)^{18}=>2.\left(x+1\right)=18\)

\(\left(x+1\right)=18:2=>\left(x+1\right)=9\)

\(x=9-1=>x=8\)

vậy \(x=8\)

25 tháng 9 2018

a) \(\left(\frac{1}{9}\right)^x=\left(\frac{1}{27}\right)^{22}\)

\(\left[\left(\frac{1}{3}\right)^2\right]^x=\left[\left(\frac{1}{3}\right)^3\right]^{22}\)

\(\left(\frac{1}{3}\right)^{2\cdot x}=\left(\frac{1}{3}\right)^{66}\)

\(\Rightarrow2\cdot x=66\)

\(x=66\div2\)

\(x=33\)
Vậy x = 33
b) \(\left(\frac{4}{9}\right)^x=\left(\frac{8}{27}\right)^6\)

\(\left[\left(\frac{2}{3}\right)^2\right]^x=\left[\left(\frac{2}{3}^3\right)\right]^6\)

\(\left(\frac{2}{3}\right)^{2\cdot x}=\left(\frac{2}{3}\right)^{18}\)

\(\Rightarrow2\cdot x=18\)

\(x=18\div2\)

\(x=9\)

Vậy x = 9

20 tháng 5 2021

a,2/5 = 2/5 ; 3/8=6/16 ; 1/9=3/27

b, 4/3=8/6 ; -1=-1 ; -4/-2=-8/4

tick cho mik nhé 

22 tháng 1 2022

a) x= 2, x= 8.(6 : 3) = 16, x= 1. (27 : 9)= 3

b) x= 6 : (8 : 4) = 3, x= -1, x= -2 . -8 = x.x => 16 = x2 => 42 = x2 => x=4

        Tick cho mình đi ok

14 tháng 7 2019

a) \(\left(\frac{4}{9}\right)^x=\left(\frac{8}{27}\right)^6\)

\(\Leftrightarrow\left(\frac{2}{3}\right)^{2x}=\left(\frac{2}{3}\right)^{18}\)

\(\Leftrightarrow2x=18\)

\(\Leftrightarrow x=9\)

14 tháng 7 2019

b) \(\left(\frac{1}{9}\right)^x=\left(\frac{1}{27}\right)^{22}\)

\(\Leftrightarrow\left(\frac{1}{9}\right)^x=\left(\frac{1}{3}\right)^{66}\)

\(\Leftrightarrow x=66\)

23 tháng 10 2016

a)27^5.3^x=9^8

3^15.3^x=3^16

3^x=3^16 : 3^15

3^x = 3^1

=> x=1

23 tháng 10 2016

b)8^x.64=4^6

8^x.8^2=8^3

8^x=8^3 : 8^2

8^x= 8^1

=> x=1