Solve 3^(2x+4) + 1 = 2·3^(x+2)

Solve: \(3^{2x+4} + 1 = 2\cdot3^{x+2}\)

Solution

\[ 3^{2x+4} + 1 = 2\cdot3^{x+2} \]

\[ \text{Let } t = 3^{x+2} \]

\[ \Rightarrow t^2 + 1 = 2t \]

\[ \Rightarrow t^2 – 2t + 1 = 0 \]

\[ \Rightarrow (t – 1)^2 = 0 \]

\[ \Rightarrow t = 1 \]

\[ \Rightarrow 3^{x+2} = 1 = 3^0 \]

\[ \Rightarrow x + 2 = 0 \]

\[ \Rightarrow x = -2 \]

Final Answer:

\[ \boxed{x = -2} \]

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