Questions: Solve the equation.
[
(x-8)^2-4(x-8)-5=0
]
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. The solution set is .
(Simplify your answer. Type an exact answer, using radicals as needed. Use a comma to separate answers as needed. Express complex numbers in terms of i.)
R. The solution set is the empty set.
Transcript text: Solve the equation.
\[
(x-8)^{2}-4(x-8)-5=0
\]
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. The solution set is $\square$ \}.
(Simplify your answer. Type an exact answer, using radicals as needed. Use a comma to separate answers as needed. Express complex numbers in terms of $i$.)
R. The solution set is the empty set.
Solution
Solution Steps
To solve the given equation, we can perform a substitution to simplify it. Let \( y = x - 8 \). This transforms the equation into a standard quadratic form: \( y^2 - 4y - 5 = 0 \). We can then solve this quadratic equation using the quadratic formula. Once we find the values of \( y \), we can substitute back to find the corresponding values of \( x \).
Step 1: Substitute and Simplify
Let \( y = x - 8 \). The original equation transforms to:
\[
y^2 - 4y - 5 = 0
\]
Step 2: Solve the Quadratic Equation
Using the quadratic formula \( y = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \) where \( a = 1, b = -4, c = -5 \):
\[
y = \frac{4 \pm \sqrt{(-4)^2 - 4 \cdot 1 \cdot (-5)}}{2 \cdot 1} = \frac{4 \pm \sqrt{16 + 20}}{2} = \frac{4 \pm \sqrt{36}}{2} = \frac{4 \pm 6}{2}
\]
This gives us two solutions for \( y \):
\[
y_1 = \frac{10}{2} = 5, \quad y_2 = \frac{-2}{2} = -1
\]