Question

Determine the reasonableness of a solution to a logarithmic equation

Answer 1

Given the question in the image, the following are the solution steps to answer the question.

STEP 1: Write the given equation

`\log_3x=7`

STEP 2: State the law of logarithm

`\begin{gathered} If\text{ }\log_ab=c \\ \Rightarrow b=a^c \\ By\text{ substitution,} \\ \therefore\log_aa^c=c \end{gathered}`

STEP 3: Substitute the given values in the question to get the correct answer

`\begin{gathered} \log_3x=7 \\ x=3^7 \\ By\text{ substitution,} \\ \log_3(3^7)=7 \end{gathered}`

Hence, Answer is:

`\log_3(3^7)=7`

OPTION A