a) x=5

b) x=0 hoặc 1

c) x=2

d) x=6 hoặc 5

e) x=0 hoặc 1

f) x=8

a, 2^x . 4 = 128

2^x = 128 : 4

2^x = 32

2^x = 2⁵

=> x = 5

b, x¹⁵ = x¹

=> x¹⁵ - x = 0

x . ( x¹⁴ - 1 ) = 0

=> x = 0 hoặc x¹⁴ - 1 = 0 

=> x = 0 hoặc x = 1

c, (2x + 1)³ = 125

( 2x + 1 )³ = 5³

=> 2x + 1 = 5

=> 2x = 5 - 1

=> 2x = 4

=> x = 4 : 2

=> x = 2

d, (x – 5)⁴ = (x - 5)⁶

=> ( x - 5 )⁶ - ( x - 5 )⁴ = 0

=> ( x - 5 )⁴ . [ ( x - 5 )² - 1 ] = 0

=> \(\orbr{\begin{cases}\left(x-5\right)^4=0\\\left(x-5\right)^2-1=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=6\end{cases}}}\)

e, x¹⁰ = x

x¹⁰ - x = 0

x . ( x⁹ - 1 ) = 0

\(\Rightarrow\orbr{\begin{cases}x=0\\x^9-1=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=1\end{cases}}}\)

f, (2x -15)⁵ = (2x -15)³

( 2x - 15 )⁵ - ( 2x - 15 )³ = 0

( 2x - 15 )³ . [ ( 2x - 15 )² - 1 ] = 0

\(\Rightarrow\orbr{\begin{cases}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{cases}\Rightarrow\orbr{\begin{cases}2x-15=0\\2x-15=1\end{cases}\Rightarrow}\orbr{\begin{cases}x\text{ không tồn tại}\\x=8\end{cases}}}\)

( 2x - 15)^5  = ( 2x - 15)^ 3 

HAi số cùng cơ số khác hệ sô bằng nhau khi hệ số bằng 1 và -1 và 0 

(+) 2x - 15 = 0 => 2x = 15 => x = 7,5

(+) 2x - 15 = 1 => 2x = 16 => x = 8

(+) 2x - 15 = -1 => 2x = 14 =>  x = 7 

`#3107`

b)

`2.3^x = 162`

`\Rightarrow 3^x = 162 \div 2`

`\Rightarrow 3^x = 81`

`\Rightarrow 3^x = 3^4`

`\Rightarrow x = 4`

Vậy, `x = 4`

c)

`(2x - 15)^5 = (2 - 15)^3`

\(\Rightarrow \)`(2x - 15)^5 - (2x - 15)^3 = 0`

\(\Rightarrow \)`(2x - 15)^3 . [ (2x - 15)^2 - 1] = 0`

\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=15\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x-15=1\\2x-15=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x=16\\2x=-14\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=-7\end{matrix}\right.\)

Vậy, `x \in`\(\left\{-7;8;\dfrac{15}{2}\right\}.\)

`d)`

\(3^{x+2}-5.3^x=?\) Bạn ghi tiếp đề nhé!

`e)`

\(7\cdot4^{x-1}+4^{x-1}=23?\)

\(4^{x-1}\cdot\left(7+1\right)=23\\ \Rightarrow4^{x-1}\cdot8=23\\ \Rightarrow4^{x-1}=\dfrac{23}{8}\)

Bạn xem lại đề!

`f)`

\(2\cdot2^{2x}+4^3\cdot4^x=1056\)

\(\Rightarrow2\cdot2^{2x}+\left(2^2\right)^3\cdot\left(2^2\right)^x=1056\\ \Rightarrow2\cdot2^{2x}+2^6\cdot2^{2x}=1056\\ \Rightarrow2^{2x}\cdot\left(2+2^6\right)=1056\\ \Rightarrow2^{2x}\cdot66=1056\\ \Rightarrow2^{2x}=1056\div66\\ \Rightarrow2^{2x}=16\\ \Rightarrow2^{2x}=2^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)

Vậy, `x = 2`

_____

\(10 -{[(x \div 3+17) \div 10+3.2^4] \div 10}=5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=10-5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=5\)

\(\Rightarrow\left(x\div3+17\right)\div10+48=50\)

\(\Rightarrow\left(x\div3+17\right)\div10=2\)

\(\Rightarrow x\div3+17=20\)

\(\Rightarrow x\div3=3\\ \Rightarrow x=9\)

Vậy, `x = 9.`

a, x= 3;2;1;0

b, x= 0;1;2;3;4;5

c, x= 0;1;2

d, x= 2;3;4;5;6

e, x= 0;1;2;3

Nho k nha

a, \(3^x.4=324\)

\(\Rightarrow\) \(3^x=81\)

\(\Rightarrow\) \(3^x=3^4\)

\(\Rightarrow\) \(x=4\)

b, \(x^{100}=x\)

\(\Rightarrow\orbr{\begin{cases}x=1\\x=0\end{cases}}\)

c, \(\left(3x-1\right)^3=125\)

\(\Rightarrow\) \(\left(3x-1\right)^3=5^3\)

\(\Rightarrow\) \(3x-1=5\)

\(\Rightarrow\) \(3x=6\)

\(\Rightarrow\) \(x=2\)

d, \(2x-15=17\)

\(\Rightarrow\) \(2x=32\)

\(\Rightarrow\)\(x=16\)

\(\left(2x-15\right)^3=\left(2x-15\right)^5\\ \Rightarrow\left(2x-15\right)^2=1\\ \Rightarrow\left[{}\begin{matrix}2x-15=-1\\2x-15=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=7\\x=8\end{matrix}\right.\)

giúp mik ik mik tic cho và nhớ cho thêm cả hướng dẫn

(2x−15)\(^3\)=(2x−15)\(^5\)

suy ra :(2x−15)\(^2\)=1

suy ra :2x−15= -1       Hoặc    2x - 15 = 1

            2x      = -1+15 HoĂc    2x    = 1+15

             2x      = 14      hoĂc     2x = 16

              x= 14: 2         hoĂc    x= 16:2 

             x= 7             hoĂc      x= 8

KL : x=7; x=8

a) x¹⁰ = 1^x

=> x¹⁰ = 1

=> x¹⁰ = 1¹⁰ => x = 1

b) x¹⁰ = x

=> x¹⁰ - x = 0

=> x(x⁹ - 1) = 0

=> \(\orbr{\begin{cases}x=0\\x^9-1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=0\\x=1\end{cases}}\)

c) x⁵ = 32 => x⁵ = 2⁵ => x = 2

d) 3^x = 81 => 3^x = 3⁴ => x = 4

e) 25^x = 125²

=> 25^x = (5³)²

=> (5²)^x = 5⁶

=> 5^2x = 5⁶

=> 2x = 6 => x = 3

f) (2x - 15)⁵ = (2x - 15)³

=> (2x - 15)⁵ - (2x - 15)³ = 0

=> (2x - 15)³ [(2x - 15)² - 1] = 0

=> \(\orbr{\begin{cases}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{cases}}\)

=> \(\orbr{\begin{cases}2x-15=0\\\left(2x-15\right)^2=1\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{15}{2}\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{cases}}\)

+) 2x - 15 = 1 => 2x = 16 => x = 8

+) 2x - 15 = -1 => 2x = 14 => x = 7

Vậy x = 8,x = 7