a) Ta có :  2 x : 2 2 = 2 5  nên x = 7.

b) Ta có:  3 x : 3 2 = 3 5  nên x = 7.

c) Ta có :  4 4 : 4 x = 4 2  nên x = 2.

d) Ta có :  5 x : 5 2 = 5 2  nên x = 4,

e) Ta có:  5 x + 1 : 5 = 5 4  nên x = 4.

f) Ta có :  4 2 x - 1 : 4 = 4 2  nên x = 2

4^2x+1+4^2x=20

4^2x.4^1+4^2x.1=20

4^2x.(4^1+1)=20

4^2x.5=20

4^2x=20:5

4^2x=4

4^2x=2^2

2x=2

x=2:2

x=1

sai đừng trách mk còn đúng thì 1 like

4^2x+1+4^2x=20

4^2x.4^1+4^2x.1=20

4^2x.(4^1+1)=20

4^2x.5=20

4^2x=20:5

4^2x=4

4^2x=2^2

2x=2

\(\Leftrightarrow3\cdot4^{2x+1}=36+156=192\)

=>2x+1=3

hay x=1

\(3.4^{2x+1}-156=72:2\)

\(3.4^{2x+1}-156=36\)

\(4^{2x+1}-156=36:3\)

\(4^{2x+1}-156=12\)

\(4^{2x+1}=12+156\)

\(4^{2x+1}=168\)

\(2x+1=168:4\)

\(2x+1=42\)

\(x+1=42:2\)

\(x+1=21\)

\(x=21-1\)

\(x=20\)

a) \(\left(x-6\right)^2=9=3^2\)

\(\Rightarrow x-6=3\) hay \(x-6=-3\)

\(\Rightarrow x=9\) hay \(x=3\)

b) \(4^{2x-6}=1=4^0\)

\(\Rightarrow2x-6=0\Rightarrow x=3\)

a) \(\left(x-6\right)^2=9\)

\(\Rightarrow\left(x-6\right)^2=3^2\)

\(\Rightarrow\left[{}\begin{matrix}x-6=-3\\x-6=3\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=6\\x=9\end{matrix}\right.\)

b) \(4^{2x-6}=1\)

\(\Rightarrow4^{2x-6}=4^0\)

\(\Rightarrow2x-6=0\)

\(\Rightarrow2x=6\)

\(\Rightarrow x=3\)

42\(x\) - 1:4 = 16

42\(x\)          = 16 + \(\dfrac{1}{4}\)

42\(x\)         = 16,25

    \(x\)       = 16,25:42

    \(x\)      = \(\dfrac{65}{168}\)

\(\Leftrightarrow2x-1=3\)

hay x=2

\(235-4^{2x-1}=171\\ \Leftrightarrow4^{2x-1}=64\\ \Leftrightarrow4^{2x-1}=4^3\\ \Leftrightarrow2x-1=3\\ \Leftrightarrow2x=4\\ \Leftrightarrow x=2\)

4^2x-1 = 81. 16 - 272

4^2x-1 = 1296 - 272

4^2x-1 = 1024

4^2x : 4 = 1024

4^2x = 1024 x 4

4^2x = 4096

4^2x = 4^2.3

=> x = 3

\(a,\Rightarrow2^{2x-5}=2^5\Rightarrow2x-5=5\Rightarrow x=5\\ b,\Rightarrow4^{2x-1}=4^3\Rightarrow2x-1=3\Rightarrow x=2\\ c,\Rightarrow\left[{}\begin{matrix}2x+2=11\\2x+2=-11\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{9}{2}\\x=-\dfrac{13}{2}\end{matrix}\right.\\ d,\Rightarrow2^{x^3}=256=2^8\Rightarrow x^3=8\Rightarrow x=2\)

a)
\(2^{2x-5}=2^5\)
2x-5=5
2x=10
x=5
b)
\(4^{2x-1}=4^3\)
2x-1=3
2x=4
x=2
c)
\(\left(2x+2\right)^2=11^2\)
2x+2=11
2x=9
x=9/2
 

42x=42x(39-37)

42x=42x2

42x=84

x=84:42=2

k nha

42x = 39 . 42 - 37 . 42

42x = 42 ( 39 - 37 )

42x = 42 . 2

42x = 84

=> x = 2