16^x<128⁴

=> 16^x<16³²

Vì n\(\in\)N => x<32 => x\(\in\){0;1;2;3;...;31}

x\(\in\)N* 16^x < 128⁴

16^x=(2⁴)^x=2^4x

128⁴=(2⁷)⁴=2^4.7

Vì 2^4x < 2^4.7

Nên x<7

Vậy x\(\in\){0;1;2;3;4;5;6}

16<2^n<128

=>2^4<2^n<2^7

Nên n=4 hoặc 5. Đúng nha!

16^x < 128⁴

= (2⁴)^x < (2⁷)⁴

= 2^4x < 2²⁸

=> 4x < 28

= 4x < 4 . 7

=> x < 7 

Vậy: x thuộc {0; 1; ... ; 6}

ta  co 128^4=16^7

Để 16^x<128^4 thi x<7

vi x la so tu nhien nen x thuoc tap hop cac so 0,1,2,3,4,5,6

16^x<128⁴

<=> (2⁴)^x < (2⁷)⁴

<=> 2 ^4x< 2²⁸

=> 4x < 28 => x < 7

Đáp số: x < 7

 a/16^x < 128^4 
=> (4^2)^x < 128^4 
=> 4^2x < 128^4 
=> (2^2)^2x < 128^4 
=> 2^4x < (2^7)^4 
=> 2^4x < 2^28 
=> 4x < 28 
=> x < 7 
vậy x = {0,1,2,3,4,5,6} 

A) X - 7= -5               

  X     = -5+7

X      =2

a) x - 7 = -5

=> x = -5 + 7

=> x = 2

b) 128 - 3 . (x + 4) = 23

=> 3.( x + 4) = 128 - 23

=> 3.( x + 4) = 105

=> x + 4 = 105 : 3

=> x + 4 = 35

=> x = 35 - 4

=> x = 31

c) [ ( 6x - 39 ) : 7 ].4 = 12

( 6x -39) : 7 = 12 :4

=> ( 6x - 39 ): 7 = 3

=> 6x - 39 = 3 x 7

=> 6x - 39 = 21

=> 6x = 21 + 39

=> 6x = 60

=> x = 60: 6

=> x = 10

d) ( x: 3 - 4) , 5 = 15

=> x: 3 - 4 = 15 : 5

=> x : 3 - 4 = 3

=> x: 3 = 3+4

=> x: 3 = 7

=> x = 7x 3

=> x =21

a) x -7=-5

      x=-5 +7

      x=2

b)128-3.(x+4)=23

       3.(x+4)=128-23

       3.(x+4)=105

             x+4=105:3

             x+4=35

                  x=35-4

                  x=31

c)[(6x-39):7].4=12

(6x-39):7=12:4

(6x-39):7=3

6x-39     =3.7

6x-39      =21

6x          =21+39

6x          =60

  x           =60:6

  x           =10

d)(x:3-4).5=15

     x:3-4.   =15:5

      x:3-4   =3

       x:3      =3+4

      x:3       =7

        x        =7.3

        x         =21

Ai thấy đúng k mk nha

16^x < 128⁴ 
=> (4²)^x < 128⁴
=> 4^2x< 128⁴
=> (2²)^2x < 128⁴
=> 2^4x < (2⁷)⁴
=> 2^4x < 2²⁸
=> 4x < 28 
=> x < 7 
vậy x = {0,1,2,3,4,5,6} 

16^x = (2⁴)^x = 2^4x

128⁴ = (2⁷)⁴ = 2²⁸

2^4x > 2²⁸ 

=> 4x < 28

=> x = {1,2,3,4,5,6}

2^4x< 2^32

=> 4x< 32

=> x<8

=> x={ 0;1;2;3;4;5;6;7}

\(16^x