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If lot 7- log 2 + log 16 - 2 log3 - log ...

If lot 7- log 2 + log 16 - 2 log3 - log `"" (7)/(45)= 1 + log `k, find the value of k.

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To solve the equation \( \log 7 - \log 2 + \log 16 - 2 \log 3 - \log \left(\frac{7}{45}\right) = 1 + \log k \), we will use properties of logarithms step by step. ### Step-by-step Solution: 1. **Apply the properties of logarithms**: - Use the property \( \log a - \log b = \log \left(\frac{a}{b}\right) \) and \( \log a + \log b = \log(ab) \). - Rewrite \( -\log 2 \) and \( -\log \left(\frac{7}{45}\right) \). \[ \log 7 - \log 2 = \log \left(\frac{7}{2}\right) \] \[ -\log \left(\frac{7}{45}\right) = \log \left(\frac{45}{7}\right) \] So, the equation becomes: \[ \log \left(\frac{7}{2}\right) + \log 16 - 2 \log 3 + \log \left(\frac{45}{7}\right) = 1 + \log k \] 2. **Combine the logarithms**: - Now combine the logarithms on the left side: \[ \log \left(\frac{7}{2} \cdot 16 \cdot \frac{45}{7}\right) - 2 \log 3 = 1 + \log k \] - The term \( -2 \log 3 \) can be rewritten as \( \log(3^{-2}) = \log \left(\frac{1}{9}\right) \). Thus, we have: \[ \log \left(\frac{7 \cdot 16 \cdot 45}{2 \cdot 9}\right) = 1 + \log k \] 3. **Simplify the expression**: - Calculate the product inside the logarithm: \[ \frac{7 \cdot 16 \cdot 45}{2 \cdot 9} = \frac{7 \cdot 16 \cdot 5}{1} = 7 \cdot 80 = 560 \] So, the equation now looks like: \[ \log(560) = 1 + \log k \] 4. **Convert 1 to logarithmic form**: - Recall that \( 1 = \log(10) \), so we can rewrite the equation: \[ \log(560) = \log(10) + \log k \] 5. **Combine the logarithms**: - Using the property \( \log a + \log b = \log(ab) \): \[ \log(560) = \log(10k) \] 6. **Equate the arguments**: - Since the logarithms are equal, their arguments must also be equal: \[ 560 = 10k \] 7. **Solve for \( k \)**: - Divide both sides by 10: \[ k = \frac{560}{10} = 56 \] ### Final Answer: The value of \( k \) is \( 56 \). ---
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