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Without using e or in, prove (image attached greatly appreciated)

Without using e or in, prove (image attached greatly appreciated)-example-1
User Gavin King
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1 Answer

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Explanation

We are required to use logarithm properties/laws to prove the given equation below:


(1)/(\log_4x)+(1)/(\log_5x)=(1)/(\log_(20)x)

This is achieved thus:

We know that the reciprocal law of logarithm states:


\log_ba=(1)/(\log_ab)

Therefore, we have:


\begin{gathered} From\text{ }the\text{ }left\text{ }hand\text{ }side, \\ (1)/(\log_4x)+(1)/(\log_5x)=\log_x4+\log_x5 \\ \\ \text{ Using the product law, we have} \\ =\log_x(4*5)=\log_x20 \\ \\ \text{ Using the reciprocal law, we have} \\ =\log_x20=(1)/(\log_(20)x) \\ \\ \text{ which is the right hand side } \end{gathered}

Hence, we have proved that:


\frac{1}{\operatorname{\log}_(4)x}+\frac{1}{\operatorname{\log}_(5)x}=\frac{1}{\operatorname{\log}_(20)x}

User Alanmars
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