Question

tim x 

16^x <128⁴

5^x.5^x+1.5^x+2 < 100...0 : 2¹⁸ ( 100...0 co 10 chu so 0 )

Answer 1

16^x<128⁴

=>(2⁴)^x<(2⁷)⁴

=>2^4x<2²⁸

=>4x<28

=>x<7

=>x=0;1;2;3;4;5;6

vậy x=0;1;2;3;4;5;6

b,=>5^x.5^x+1.5^x+2<10¹⁰:2¹⁸

=>5^3x+3<5¹⁰.2¹⁰:2¹⁸

=>5^3x+3<5¹⁰.2⁸

=>5^3x+3:5¹⁰<2⁸

=>5^3(x+1)-10<256<5⁴

=>3(x+1)-10<4

=>3(x+1)<4+10

=>x+1<14/3<5

=>x<4

=>x=0;1;2;3

vậy x=0;1;2;3

 

Answer 2

       16^x < 128^4

=>    2^4x  < 2^7.4 

=> 2 ^4x   < 2^28

=> 4x < 28 

=> x < 7 

Answer 3

16x<1284

=>(24)x<(27)4

=>24x<228

=>4x<28

=>x<7

=>x=0;1;2;3;4;5;6

vậy x=0;1;2;3;4;5;6

b,=>5x.5x+1.5x+2<1010:218

=>53x+3<510.210:218

=>53x+3<510.28

=>53x+3:510<28

=>53(x+1)-10<256<54

=>3(x+1)-10<4

=>3(x+1)<4+10

=>x+1<14/3<5

=>x<4

=>x=0;1;2;3

vậy x=0;1;2;3