Use logarithms to solve the equation \(2^{5x} = 3^{2x+1}\), giving the answer correct to 3 significant figures.
Solution
Take the natural logarithm of both sides of the equation:
\(\ln(2^{5x}) = \ln(3^{2x+1})\)
Apply the power rule for logarithms: \(a \ln(b) = \ln(b^a)\).
\(5x \ln(2) = (2x+1) \ln(3)\)
Expand the right side:
\(5x \ln(2) = 2x \ln(3) + \ln(3)\)
Rearrange to solve for \(x\):
\(5x \ln(2) - 2x \ln(3) = \ln(3)\)
Factor out \(x\):
\(x (5 \ln(2) - 2 \ln(3)) = \ln(3)\)
Solve for \(x\):
\(x = \frac{\ln(3)}{5 \ln(2) - 2 \ln(3)}\)
Calculate \(x\) to 3 significant figures:
\(x \approx 0.866\)
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