3 ² . (1:243). 81 ² . (1:3)² = ?
3,5 khác với 3.5 
bài của Hải muốn hỏi vậy sao?

\(\dfrac{8}{25}=\dfrac{2^x}{5^{x-1}}\)

\(\Leftrightarrow\dfrac{2^x}{5^x.\dfrac{1}{5}}=\dfrac{8}{25}\)

\(\Leftrightarrow\dfrac{2^x}{5^x}.\dfrac{1}{\dfrac{1}{5}}=\dfrac{8}{25}\)

\(\Leftrightarrow\dfrac{2^x}{5^x}.5=\dfrac{8}{25}\)

\(\Leftrightarrow\dfrac{2^x}{5^x}=\dfrac{8}{125}\)

\(\Leftrightarrow\left(\dfrac{2}{5}\right)^x=\left(\dfrac{2}{5}\right)^3\Rightarrow x=3\)

`8/25=[2^x]/[5^[x-1]]`

`=>[2^3]/[5^2]=[2^x]/[5^[x-1]]`

`=>{(3=x),(2=x-1):}`

`=>{(x=3),(x=3):}`

`=>x=3`

`2+|1-2x|=5`

`=>|1-2x|=3`

`=>` $\left[\begin{matrix} 1-2x=3\\ 1-2x=-3\end{matrix}\right.$

`=>` $\left[\begin{matrix} -2x=2\\ -2x=-4\end{matrix}\right.$

`=>` $\left[\begin{matrix} x=-1\\ x=2\end{matrix}\right.$

2023 ¹⁰¹¹  so với 2. 2022 ¹⁰¹¹

bài như vậy?

`2^n : 2 = 8`

`2^n = 8 xx 2`

`2^n = 16`

`2^n = 2^4`

`=> n=4`

________________________

`3^n . 2^3 = 6^3`

`3^n . 8 = 216`

`3^n = 216 : 8`

`3^n = 27`

`=> 3^n = 3^3`

`=> n=3`

a) \(2^n=8\Leftrightarrow2^n=2^3\Leftrightarrow n=3\)

b) \(2^n:2=8\Leftrightarrow2^n=4\Leftrightarrow n=2\)

c) \(2^n.4=16\Leftrightarrow2^n=4\Leftrightarrow n=2\)

d)\(3^n.2^3=6^3\Leftrightarrow3^n=27\Leftrightarrow n=3\)

e) \(3^x.3=243\Leftrightarrow3^x=81\Leftrightarrow x=4\)