Question

tìm x biết 3^{x + 1} = 9^x

 

 

Answer 1

\(3^{x+1}=9^x\\ \Leftrightarrow3^{x+1}=3^{2x}\\ \Leftrightarrow x+1=2x\\ \Leftrightarrow x=1\)

Answer 2

\(VP=9^x=\left(3^2\right)^x=3^{2x}\\ Vì:3^{x+1}=9^x=3^{2x}\\ Nên:x+1=2x\\ \Rightarrow2x-x=1\\ Vậy:x=1\)

Answer 3

\(3^{x+1}=9^x\\ \Rightarrow3^{x+1}=3^{3x}\\ \Rightarrow x+1=3x\\ \Rightarrow1=2x\\ \Rightarrow x=\dfrac{1}{2}.\)

Answer 4

3^x+1= 3^2x

=> x+1 = 2x

Answer 5

Sửa lại:

\(3^{x+1}=9^x\\ \Rightarrow3^{x+1}=3^{2x}\\ \Rightarrow x+1=2x\\ \Rightarrow x=1.\)