What is the solution to this equation?

[tex]\[ \left(\frac{1}{4}\right)^{x+1}=32 \][/tex]

A. 2

B. [tex]\[ -\frac{7}{2} \][/tex]

C. -2

D. [tex]\[ \frac{3}{2} \][/tex]



Answer :

To solve the given equation

[tex]\[ \left(\frac{1}{4}\right)^{x+1} = 32, \][/tex]

we'll proceed step-by-step as follows:

1. Write both sides of the equation with the same base:

Recall that [tex]\(\frac{1}{4}\)[/tex] can be written as [tex]\(4^{-1}\)[/tex] and [tex]\(32\)[/tex] can be written as [tex]\(2^5\)[/tex].

So the equation becomes:
[tex]\[ (4^{-1})^{x+1} = 32 \][/tex]

2. Simplify the left side:

Applying the power rule [tex]\((a^m)^n = a^{mn}\)[/tex], we get:
[tex]\[ 4^{-(x+1)} = 32 \][/tex]

3. Express 32 as a power of 4:

To further simplify, note that 32 can be written as [tex]\(2^5\)[/tex]. Now we need to express [tex]\(2^5\)[/tex] in terms of a base that involves 4. Remember [tex]\(4 = 2^2\)[/tex], and therefore:
[tex]\[ 32 = 2^5 = (2^2)^{2.5} = 4^{2.5} \][/tex]

4. Set the exponents equal to each other:

Since [tex]\(4^{-(x+1)} = 4^{2.5}\)[/tex], the exponents must be equal:
[tex]\[ -(x + 1) = 2.5 \][/tex]

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

Solve the equation [tex]\(-(x + 1) = 2.5\)[/tex]:
[tex]\[ -x - 1 = 2.5 \][/tex]
Adding 1 to both sides:
[tex]\[ -x = 3.5 \][/tex]
Multiplying both sides by -1:
[tex]\[ x = -3.5 \][/tex]

Therefore, the solution to the equation [tex]\(\left(\frac{1}{4}\right)^{x+1} = 32\)[/tex] is

[tex]\[ \boxed{-\frac{7}{2}} \][/tex]

which corresponds to option B.