Solve for [tex]\( x \)[/tex]:
[tex]\[ 4^{x-1} = \log_8 64 \][/tex]

(A) [tex]\( x = \frac{1}{2} \)[/tex]

(B) [tex]\( x = \frac{3}{2} \)[/tex]

(C) [tex]\( x = \frac{5}{2} \)[/tex]

(D) [tex]\( x = 1 \)[/tex]

(E) [tex]\( x = 3 \)[/tex]



Answer :

Let's solve the equation [tex]\( 4^{x-1} = \log_8 64 \)[/tex] step-by-step.

1. Evaluate the logarithm:

We start by solving [tex]\( \log_8 64 \)[/tex]. This asks: to what power must 8 be raised to get 64?

Notice that:
[tex]\[ 8^2 = 64 \][/tex]
Therefore:
[tex]\[ \log_8 64 = 2 \][/tex]

2. Substitute the logarithm back into the equation:

With [tex]\( \log_8 64 = 2 \)[/tex], the original equation [tex]\( 4^{x-1} = \log_8 64 \)[/tex] simplifies to:
[tex]\[ 4^{x-1} = 2 \][/tex]

3. Rewrite the equation with a common base:

Next, it helps to express both sides of the equation using the same base. We know that:
[tex]\[ 4 = 2^2 \][/tex]
So:
[tex]\[ 4^{x-1} = (2^2)^{x-1} = 2^{2(x-1)} \][/tex]

Now our equation looks like this:
[tex]\[ 2^{2(x-1)} = 2^1 \][/tex]

4. Set the exponents equal to each other:

Since the bases are the same, we can set the exponents equal to each other:
[tex]\[ 2(x-1) = 1 \][/tex]

5. Solve for [tex]\( x \)[/tex]:

Now, we solve the equation for [tex]\( x \)[/tex]:
[tex]\[ 2(x-1) = 1 \][/tex]
[tex]\[ 2x - 2 = 1 \][/tex]
[tex]\[ 2x = 3 \][/tex]
[tex]\[ x = \frac{3}{2} \][/tex]

Thus, the solution to the equation [tex]\( 4^{x-1} = \log_8 64 \)[/tex] is [tex]\( x = \frac{3}{2} \)[/tex], which corresponds to option (B).

So, the correct answer is:
[tex]\[ \boxed{\frac{3}{2}} \][/tex]