Question
Solve log8(x2−9)−log89=1 .(1 point) Responses x=±17−−√ x equals plus or minus Start Root 17 End Root x=±32–√ x equals plus or minus 3 Start Root 2 End Root x=9,−9 x equal 9 comma negative 9 x=9
Answers
GPT-4o mini
To solve the equation \( \log_8(x^2 - 9) - \log_8(9) = 1 \), we can use the properties of logarithms.
1. Use the property of logarithms: \( \log_b(a) - \log_b(c) = \log_b\left(\frac{a}{c}\right) \).
\[
\log_8\left(\frac{x^2 - 9}{9}\right) = 1
\]
2. Rewrite the equation using the definition of logarithms: If \( \log_b(a) = c \), then \( a = b^c \).
\[
\frac{x^2 - 9}{9} = 8^1
\]
This simplifies to:
\[
\frac{x^2 - 9}{9} = 8
\]
3. Multiply both sides by 9:
\[
x^2 - 9 = 72
\]
4. Add 9 to both sides:
\[
x^2 = 81
\]
5. Take the square root of both sides:
\[
x = \pm 9
\]
Thus, the solutions are \( x = 9 \) and \( x = -9 \).
The correct response is:
**x = 9, −9 (x equals 9, negative 9)**.
1. Use the property of logarithms: \( \log_b(a) - \log_b(c) = \log_b\left(\frac{a}{c}\right) \).
\[
\log_8\left(\frac{x^2 - 9}{9}\right) = 1
\]
2. Rewrite the equation using the definition of logarithms: If \( \log_b(a) = c \), then \( a = b^c \).
\[
\frac{x^2 - 9}{9} = 8^1
\]
This simplifies to:
\[
\frac{x^2 - 9}{9} = 8
\]
3. Multiply both sides by 9:
\[
x^2 - 9 = 72
\]
4. Add 9 to both sides:
\[
x^2 = 81
\]
5. Take the square root of both sides:
\[
x = \pm 9
\]
Thus, the solutions are \( x = 9 \) and \( x = -9 \).
The correct response is:
**x = 9, −9 (x equals 9, negative 9)**.