Question

e, 2 mũ x .4 =128

f , ( x-5) mũ 4 = (x- 5) mũ 6

( 7x -11) ^3 =2^5 .5^ 2 .200

49 . 7^x =2041

Answer 1

e, 2^x.4 = 128

<=> 2^x . 2² = 2⁷

=> x + 2 = 7

<=> x = 5

Vậy x = 5

f , ( x - 5)⁴ = (x - 5)⁶

<=> ( x - 5)⁴ - (x - 5)⁶ =0

<=> (x - 5)⁴. [1 - (x - 5)²] = 0

<=> (x - 5)⁴ (1 - x + 5)(1 + x - 5) = 0

<=> (x - 5)⁴ (6 - x)(x - 4) = 0

<=> \(\left[{}\begin{matrix}x-5=0\\6-x=0\\x-4=0\end{matrix}\right.\) <=> \(\left[{}\begin{matrix}x=5\\x=6\\x=4\end{matrix}\right.\)

Vậy x ={5; 6; 4}

49 . 7^x = 2041

<=> 7². 7^x = 7⁴

=> 2 + x = 4

<=> x = 2

Vậy x = 2

Answer 2

https://i.imgur.com/56c7Aqq.jpg