Question

Tìm x

4^x=2^x+1

16=(x-1)⁴

Answer 1

16=(x-1)⁴

(x-1)⁴=16

(x-1)⁴=2⁴

=>x-1=2

x=2+1

x=3

Answer 2

a) 4^x=2^x+1

=> (2²)^x=2^x+1

=> 2^2x=2^x+1

=> 2x=x+1

=>x=1

b) 16=(x-1)⁴

=> (x-1)⁴ =(-2)⁴;2⁴

Xet (x-1)⁴=(-2)⁴

=> x-1=-2

=> x=-1

Xet (x-1)⁴=2⁴

=> x-1=2

=> x=3

Vậy x=-1;3 

Answer 3

4^x=2^x+1
 (2²)^x=2^x+1

2^2x=2^x+1

=>2x=x+1

vậy x=1