Question

Tìm x:

a) ( 3x - 1 )^3 = 27

b) 3 ^2x - 1 = 27

c) 6 ^8 - 2x = 36

d) ( 3x - 2 )^10 = ( 3x - 2 )^7

*Đằng sau dấu "^" ý chỉ là những số mũ nhé!!!

Answer 1

a) (3x-1)³ = 27 = 3³

=> 3x - 1 = 3

3x = 4

x = 4/3

b) 3^2x-1 = 27 = 3³

=> 2x - 1 = 3

2x = 4

x = 2

c) 6^8-2x = 36 = 6²

=> 8 -2x = 2

=> 2x = 6

x = 3

d) (3x-2)¹⁰ = (3x-2)⁷

=> (3x-2)¹⁰ - (3x-2)⁷ = 0

(3x-2)⁷. [(3x-2)³ - 1] = 0

=> (3x-2)⁷ = 0 => 3x-2 = 0 => 3x = 2 => x = 2/3

(3x-2)³ - 1 = 0 => (3x-2)³ =  1 => 3x - 2 = 1 => 3x = 3 => x = 1

KL:...

Answer 2

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

\(3x-1=3=>3x=4\)

\(=>x=\frac{4}{3}\)