Question

tìm x biết:

a.8^x=64²  

b.3^x+1 = 27

c.4^2x=1024⁴

Ai nhanh mk tick

 

Answer 1

a) 8^x = 64²

=> 8^x = 8⁴

=> x = 4

b) 3^{x + 1} = 27

=> 3^{x + 1} = 3³

=> x + 1 = 3

=>  x = 3 - 1 = 2

c) 4^2x = 1024⁴

=> 4^2x = 4²⁰

=> 2x = 20

=> x = 20 : 2

=> x = 10

Answer 2

a) x=4

b)3\(^{\left(2+1\right)}\)=27

c)x=20

Answer 3

a,\(^{8^x=64^2=8^4=>x=4}\)

b\(3^{x+1}=27=3^3=>x+1=3< =>x=2\)

c\(4^{2x}=1024^4=4^{20}=>2x=20< =>x=10\)

Answer 4

8^x = 64²

 8^x = ( 8² )²

 8^x = 8⁴

\(\Rightarrow\) x= 4

Vậy x = 4

b. 3^{x + 1} = 27

  3^{x + 1} = 3³

 \(\Rightarrow\) x + 1 = 3

          x = 3 - 1

          x = 2

Vậy x = 2

c. 4^2x = 1024⁴

4^2x = ( 4⁵ )⁴

4^2x = 4²⁰

\(\Rightarrow\) 2x = 20

          x = 10

Vậy x = 10

  

Answer 5

a) 8^x = 64²

=> (2³)^x = (2⁶)²

=> 2^3x = 2¹²

=>   3x = 12

=>     x = 12 : 3

=>     x = 4

b) 3^{x + 1} = 3³

=> x + 1 = 3

=> x       = 3 - 1

=> x       = 2

c) 4^2x = 1024⁴

=> (2²)^2x = (2¹⁰)⁴

=> 2^2.2x   = 2^10.4

=> 2^4x      = 2⁴⁰

=> 4x       = 40

=>   x       = 40 : 4

=>   x       = 10