`4^(x+4)-4^x =4080`

`=>4^x *4^4 -4^x =4080`

`=>4^x (256-1)=4080`

`=>4^x *255=4080`

`=>4^x =16`

`=>4^x =4^2`

`=>x=2`

Trả lời giúp mình câu này

a,9/8-(2x+1)=7/4

<=>2x+1=-5/8

<=>2x=-13/8

<=>x=-13/16

b,3/4+1/4.x=7/4

<=>1/4.x=1

<=>x=4

\(\left(x-4\right)^2=\left(x-4\right)^4\)

\(\Rightarrow\left(x-4\right)^2-\left(x-4\right)^4=0\)

\(\Rightarrow\left(x-4\right)^2-\left(x-4\right)^2.\left(x-4\right)^2=0\)

\(\Rightarrow\left(x-4\right)^2.\left[1-\left(x-4\right)^2\right]=0\)

TH 1 : \(\left(x-4\right)^2=0\Rightarrow x-4=0\Rightarrow x=4\)

TH 2 : \(1-\left(x-4\right)^2=0\Rightarrow\left(x-4\right)^2=1\Rightarrow\orbr{\begin{cases}x-4=1\\x-4=-1\end{cases}}\Rightarrow\orbr{\begin{cases}x=5\\x=3\end{cases}}\)

Vậy x = 3; x = 4 hoặc x = 5

x = 4  nha 

\(4^x+4^{x+2}-4^x+1=832\)

de bai cua mk dung ko

 (x - 4)² = (x - 4)⁴

<=> (x - 4)² - (x - 4)⁴ = 0

<=>  (x - 4)² [ 1 -  (x - 4)² ] = 0

<=> \(\orbr{\begin{cases}\left(x-4\right)^2=0\\1-\left(x-4\right)^2=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x-4=0\\\left(x-4\right)^2=1\end{cases}\Leftrightarrow\orbr{\begin{cases}x-4=0\\\left(x-4\right)^2=1\end{cases}}}\)

Giải (x - 4)² = 1

TH1: x - 4 = -1

<=> x = 3

TH2: x - 4 = 1

<=> x = 5

\(\left(x-4\right)^2-\left(x-4\right)^4=0\)

\(\Leftrightarrow\left(x-4\right)^2\left(1-\left(x-4\right)^2\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-4=0\\\left(x-4\right)^2=1\end{cases}}\)\(\Rightarrow\hept{\begin{cases}x=4\\x=3\\x=5\end{cases}}\)