Which logarithmic equation has the same solution as [tex]$x - 4 = 2^3$[/tex]?

A. [tex]\log 3^2 = (x - 4)[/tex]

B. [tex]\log 2^3 = (x - 4)[/tex]

C. [tex]\log_2 (x - 4) = 3[/tex]

D. [tex]\log_3 (x - 4) = 2[/tex]



Answer :

To determine which logarithmic equation matches the solution of the equation [tex]\(x - 4 = 2^3\)[/tex], let us follow a detailed step-by-step process:

1. First, consider the given equation [tex]\(x - 4 = 2^3\)[/tex].

2. Evaluate the right-hand side:
[tex]\[ 2^3 = 8 \][/tex]

3. The equation now becomes:
[tex]\[ x - 4 = 8 \][/tex]

4. To solve for [tex]\(x\)[/tex], add 4 to both sides of the equation:
[tex]\[ x = 8 + 4 \][/tex]
[tex]\[ x = 12 \][/tex]

Thus, [tex]\(x = 12\)[/tex] is the solution to the equation [tex]\(x - 4 = 2^3\)[/tex].

Now, let's find the logarithmic equation that has the same solution as [tex]\(x - 4 = 2^3\)[/tex]:

To match the solution to the logarithmic form, note that the equation can also be written as an exponential function in the form of logarithms. Observe the options provided:

1. [tex]\(\log 3^2 = (x - 4)\)[/tex]

2. [tex]\(\log 2^3 = (x - 4)\)[/tex]

3. [tex]\(\log _2(x - 4) = 3\)[/tex]

4. [tex]\(\log _3(x - 4) = 2\)[/tex]

Consider each option to see which one corresponds to the original equation:

- Option 1: [tex]\(\log 3^2 = (x - 4)\)[/tex]

This simplifies to:
[tex]\[ \log 9 = (x - 4) \][/tex]

To check if [tex]\(x = 12\)[/tex] fits:
[tex]\[ \log 9 = (12 - 4) \][/tex]
[tex]\[ \log 9 \neq 8 \][/tex]
Therefore, this is not the correct equation.

- Option 2: [tex]\(\log 2^3 = (x - 4)\)[/tex]

This simplifies to:
[tex]\[ \log 8 = (x - 4) \][/tex]

To check if [tex]\(x = 12\)[/tex] fits:
[tex]\[ \log 8 = (12 - 4) \][/tex]
[tex]\[ \log 8 \neq 8 \][/tex]
Therefore, this is not the correct equation.

- Option 3: [tex]\(\log _2(x - 4) = 3\)[/tex]

Using the solution [tex]\(x = 12\)[/tex]:
[tex]\[ \log _2(12 - 4) = 3 \][/tex]
[tex]\[ \log _2(8) = 3 \][/tex]

We know that:
[tex]\[ 2^3 = 8 \][/tex]
Therefore, [tex]\(\log _2 8 = 3\)[/tex], which is true. This matches the given solution.

- Option 4: [tex]\(\log _3(x - 4) = 2\)[/tex]

Using the solution [tex]\(x = 12\)[/tex]:
[tex]\[ \log _3(12 - 4) = 2 \][/tex]
[tex]\[ \log _3(8) = 2 \][/tex]

We know that:
[tex]\[ 3^2 = 9 \implies \log _3 9 = 2 \][/tex]
However, [tex]\(8 \neq 9\)[/tex], so this is not the correct equation.

Thus, the logarithmic equation that has the same solution as [tex]\(x - 4 = 2^3\)[/tex] is:

[tex]\[ \boxed{\log_2(x - 4) = 3} \][/tex]