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Solve: 6^x+1= 4^2x-1
Give 4 decimal places no rounding.

1 Answer

3 votes

Answer:


\sf x \approx 3.2402

Explanation:

To solve the equation
\sf 6^(x+1) = 4^(2x-1), we can use logarithms to simplify it.

Let's take the logarithm (base 10) of both sides:


\sf \log_(10)(6^(x+1)) = \log_(10)(4^(2x-1))

Now, we can use the logarithmic properties to simplify the exponents:


\sf (x+1) \cdot \log_(10)(6) = (2x-1) \cdot \log_(10)(4)

Now, let's solve for
\sf x:


\sf x \cdot \log_(10)(6) + \log_(10)(6) = 2x \cdot \log_(10)(4) - \log_(10)(4)

Group
\sf x terms on one side and constants on the other:


\sf x \cdot \log_(10)(6) - 2x \cdot \log_(10)(4) = -\log_(10)(4) - \log_(10)(6)

Factor out
\sf x:


\sf x \cdot (\log_(10)(6) - 2 \cdot \log_(10)(4)) = -\log_(10)(4) - \log_(10)(6)

Now, solve for
\sf x:


\sf x = -(\log_(10)(4) + \log_(10)(6))/(\log_(10)(6) - 2 \cdot \log_(10)(4))

Now, use a calculator to evaluate this expression. Keep in mind that:


\sf \log_(10)(4) \approx 1.3862943611198 and
\sf \log_(10)(6) \approx 1.7917594692280:


\sf x \approx -(1.3862943611198 + 1.7917594692280)/(1.7917594692280 - 2 \cdot 1.3862943611198)


\sf x \approx -(3.1780538303478)/(−0.9808292530116)


\sf x \approx 3.240170315668


\sf x \approx 3.2402 \textsf{ ( in 4 decimal places)}

Therefore, the solution to the equation
\sf 6^(x+1) = 4^(2x-1) with four decimal places is
\sf x \approx 3.2402.

User Alex Dvoretsky
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