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} 

\(a,2^x.4=128\)

\(\Leftrightarrow2^x=128:4\)

\(\Leftrightarrow2^x=32\)

\(\Leftrightarrow2^x=2^5\)

\(\Rightarrow x=5\)

\(b,2^x=4.128\)

\(\Leftrightarrow2^x=2^2.2^7\)

\(\Leftrightarrow2^x=2^9\)

\(\Rightarrow x=9\)

\(c,3^x=3^3.3^5\)

\(\Leftrightarrow3^x=3^8\)

\(\Rightarrow x=8\)

\(d,2^x.\left(2^2\right)^3=\left(2^3\right)^2\)

\(\Leftrightarrow2^x.2^6=2^6\)

\(\Leftrightarrow2^x=2^6:2^6\)

\(\Leftrightarrow2^x=1\)

\(\Rightarrow x=0\)

Trả lời:

a, 2^x . 4 = 128

=> 2^x = 32

=> 2^x = 2⁵

=> x = 5

b, 2^x = 4.128

=> 2^x = 512

=> 2^x = 2⁹

=> x = 9

c, 3^x = 3³ . 3⁵ 

=> 3^x = 3⁸

=> x = 8

d, 2^x ( 2² )³ = ( 2³ )²

=> 2^x . 2⁶ = 2⁶

=> 2^x = 1

=> 2^x = 2⁰

=> x = 0

2^x . 4 = 128

2^x = 128 : 4

2^x = 32

2^x = 2^5

=> x = 5

\(2^x.4=128\)

\(\Leftrightarrow2^x=32\)

\(\Leftrightarrow2^x=2^5\)

\(\Leftrightarrow x=5\)

Vậy x = 5

Tìm x thuộc N ,biết :

\(2^x\)\(.4=128\)

\(2^x\)\(=\)\(128\div4\)

\(2^x\)\(=\)\(32\)

\(2^x\)\(=\)\(2^5\)

\(x=5\)

\(Hok\)\(Tốt\)

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

=>16^x<128⁴

=>(2^x)⁴<(2⁷)⁴

=>2^x<2⁷

=>x<7

Vì x thuộc N => x thuộc {0;1;2;3;4;5;6}

Ta có : \(16^x< 128^4\left(x\in N\right)\)

\(\Rightarrow x\in\left\{0;1;2;3;4;5;6\right\}\)

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}