4. evaluate the logarithm. a (log_{3}81 = square)

Explanation:

Step1: Rewrite 81 as power of 3

$81 = 3^4$

Step2: Apply logarithm power rule

$\log_{3}3^4 = 4\log_{3}3$

Step3: Evaluate $\log_{3}3$

$\log_{3}3 = 1$, so $4\times1=4$

Answer:

4