Solve the exponential equation

00:00 5 marks

Solve the equation $2^{2x+1} = 3 \times 5^x$ for $x$, giving your answer correct to three significant figures. [5]

Hint Hint

Hint

Rewrite $2^{2x+1}$ as $2 \times 4^x$, then divide both sides by $5^x$ to obtain $(4/5)^x = 3/2$. Taking natural logarithms will help isolate $x$.

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Answer Answer

Complete Answer

x = ln(3/2) / ln(4/5) ≈ -1.82

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Answer Explanation Answer Explanation

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Common Errors Common Errors

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