Question

\(3^x.81^{2x+1}=81\)

Tìm x thuộc N

 

Answer 1

3^x . 81^{2x + 1} = 81

3^x . 3^{8x + 4} = 81

3^{x + 8x + 4} = 3⁴

=> x + 8x + 4 = 4

=> x + 8x = 0

=> 9x = 0

=> x = 0

Vậy x = 0

Answer 2

\(3^x.81^{2x+1}=81\)

\(\Rightarrow3^x.3^{8x+4}=81\)

\(\Rightarrow3^{9x+4}=3^4\)

\(\Rightarrow9x+4=4\Leftrightarrow x=0\)

Answer 3

\(3^x\cdot81^{2x+1}=81\Rightarrow3^x\cdot3^{8x+4}=3^4\Rightarrow3^{9x+4}=3^4\Rightarrow9x+4=4\Rightarrow x=0\)