SOLUTION: Evaluate the following expression: Log5 1/25

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Question 173435: Evaluate the following expression:
Log5 1/25
Answer by solver91311(24713) About Me  (Show Source):
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log%285%2C%281%2F25%29%29

Remember the definition: y=log%28b%2C%28x%29%29 if and only if b%5Ey=x

So: y=log%285%2C%281%2F25%29%29 if and only if 5%5Ey=1%2F25. Since 25=5%5E2, 1%2F25=5%5E-2, so y=-2.

Hence: log%285%2C%281%2F25%29%29=-2