\(a,4^{2x-6}=1\)\(\Leftrightarrow2x-6=0\Leftrightarrow2x=6\Rightarrow x=3\)

\(b,2^{2x-1}=16\Rightarrow2^{2x-1}=2^4\)

\(\Rightarrow2x-1=4\Rightarrow2x=5\Rightarrow x=\frac{5}{2}\)

\(c,5< 5^x< 125\Rightarrow5^1< 5^x< 5^3\)\(\Rightarrow1< x< 3\)

\(d,5^{x+1}=125\Rightarrow5^{x+1}=5^3\Rightarrow x+1=3\Rightarrow x=2\)

\(a,4^{2x-6}=1\)

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

\(\Rightarrow2x-6=0\)

\(\Rightarrow2x=6\Leftrightarrow x=3\)

\(b,2^{x-1}=16\)

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

\(\Rightarrow x-1=4\)

\(\Rightarrow x=5\)

Nếu bài dễ thì cố gắng tự làm bạn nhé.

Bài 1:

a) \(2x+3=5\)

\(\Leftrightarrow2x=5-3=2\)

\(\Leftrightarrow x=2:2=1\)

Vậy: x=1

b) \(\left(2x-3\right)^2=9\)\(=3^2=\left(-3\right)^2\)

\(\Rightarrow\left[{}\begin{matrix}2x-3=3\\2x-3=-3\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\left(3+3\right):2=3\\x=\left(-3+3\right):2=0\end{matrix}\right.\)

Vậy: \(x\in\left\{3;0\right\}\)

c) \(3x+4=2x-7\)

\(\Leftrightarrow2x-3x=7+4\)

\(\Leftrightarrow-1x=11\)

\(\Leftrightarrow x=-11\)

Vậy: x=-11

d) \(\left(4x-1\right)^3=27\)\(=3^3\)

\(\Rightarrow4x-1=3\)

\(\Leftrightarrow4x=3+1=4\)

\(\Leftrightarrow x=4:4=1\)

Vậy: x=1

e) \(\left(x-7\right).2=3.\left(2x+4\right)\)

\(\Leftrightarrow2x-14=6x+12\)

\(\Leftrightarrow2x-6x=12+14\)

\(\Leftrightarrow-4x=26\)

\(\Leftrightarrow x=\frac{26}{-4}=\frac{13}{-2}\)

Vậy: \(x=\frac{13}{-2}\)

a)15.10² : (2x - 6) = 30

15 . 100 : (2x - 6) = 30

100 : (2x - 6) = 30 : 15

100 : (2x - 6) = 2

2x - 6 = 100 : 2

2x - 6 = 50

2x = 50 + 6

2x = 56

x = 56 : 2

x =28

b) (2x + 1 )³ =125

(2x + 1 )³ = 5³

Suy ra 2x + 1 = 5

2x = 5 - 1

2x = 4

x = 4:2

x = 2

a )15.10²:(2x-6)=30

15.100:(2x-6)=30

     100:(2x-6)=30:15

     100:(2x-6)=2

             2x-6 = 100:2

             2x-6 = 50

             2x    = 50+6

             2x    = 56

               x    = 56:2

              x     = 28

ý b) m chịu

a) 5^x = 125

\(\Rightarrow\)5^x = 5³

\(\Rightarrow\)x = 3

b, 3^2x = 81

\(\Rightarrow\)3^2x = 3⁴

\(\Rightarrow\)2x = 4

\(\Rightarrow\)  x = 4 : 2

\(\Rightarrow\)  x = 2

c, 5^2x-3 - 2 . 5² = 5² . 3

5^2x-3 - 2 . 25 = 25 . 3

5^2x-3 - 50 = 75

5^2x-3 = 75 + 50

5^2x-3 = 125

5^2x-3 = 5³

2x - 3 = 3

2x = 3 + 3

2x = 6

  x = 6 : 2

  x = 3

a, 5^x = 125 suy ra 5^x = 5³ suy ra x = 3

b, 3^2x = 81 suy ra 3^2x = 3⁴ suy ra x = 2

c, 5^{2x - 3} - 2.5² = 5² . 3

suy ra 5^2x : 5³ = 5² .3 + 2. 5²

suy ra 5^2x : 5³ = 5² . 5

suy ra 5^2x = 5³ . 5² . 5³

5^2x = 5⁶ suy ra 2x = 6 suy ra x = 3

a)5^x+1=125

5^x+1=5³

Suy ra:x+1=3

            x =3—1

x =2

\(\left(2x-1\right)^3=27\)

\(2x-1=3\)

\(2x=4\)

\(x=2\)

a)=1

b)=2

c)=khong biet

d)=khong biet

a)  1999^{2x - 6} = 1 

1999^{2x - 6} = 1999⁰

=>2x-6=0

2x=0+6

2x=6

x=6:2

x=3

b)  2^x x 4 = 128

2^x=128:4

2^x=32

2^x=2⁵

=>x=5

c)  ( 2x + 1 ) ³ = 125

( 2x + 1 ) ³ = 5³

2x+1=5

2x=5-1

2x=4

x=4:2

x=2

a)1999^2x-6=1

1999^2x-6=1999⁰

=>2x-6=0

2x=0+6

2x=6

x=6:2

x=3

b)2^x.4=128

2x=128:4

2x=32

x=32:2

x=5

c)(2x+1)³=125

(2x+1)³=5³

2x+1=5

2x=5-1

2x=4

x=4:2

x=2

câu b nhé

vì 5^3 =25

suy ra 2x+1=5

2x=5-1

2x=4

x=4/2

x=2

a/ \(2^x+2^{x+2}=144\)

\(\Rightarrow2^x+2^x.2^2=144\)

\(\Rightarrow2^x\left(2^2+1\right)=144\)

\(\Rightarrow2^x=\dfrac{144}{5}\)

\(\Rightarrow2^x=28.8\)

\(\Rightarrow x=4,847996907\) (ở câu này mk nghĩ đề sai)

b/ \(\left(2x+1\right)^3=125\)

\(\Rightarrow\left(2x+1\right)^3=5^3\)

\(\Rightarrow2x+1=5\)

\(\Rightarrow x=\dfrac{5-1}{2}=2\)

Vậy \(x=2\)