Evaluating logarithmic expressions

Evaluate each expression.
(a) $\log_{7} \frac{1}{49} = ◻$
(b) $\log_{3} 81 =$

Answer

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Answer

\boxed{4}

Steps

Step 1 ：To solve this, we need to find the power to which 7 must be raised to get 1/49.

Step 2 ：We know that $7^{2} = 49$ , so $7^{- 2} = 1 / 49$ .

Step 3 ： $\log_{7} \frac{1}{49} = - 2$

Step 4 ：\boxed{-2}

Step 5 ：To solve this, we need to find the power to which 3 must be raised to get 81.

Step 6 ：We know that $3^{4} = 81$ .

Step 7 ： $\log_{3} 81 = 4$

Step 8 ：\boxed{4}