19
QuizMultiple Choice

Exponential and Logarithmic Functions — Test

Question 19 • Algebra II

What is the solution to 2 log sub 9 x is equal to log sub 9 8 plus log sub 9 of open paren x minus 2 close paren ?

Answer
A
x is equal to negative 2
B
x is equal to 4
C
x is equal to 8
D
x is equal to negative 4

Explanation

The logarithms require x > 2, so the expressions are defined. Use the log rules: 2 log₉ x = log₉(x²), and log₉ 8 + log₉(x − 2) = log₉(8(x − 2)). Since the bases match, set the arguments equal: x² = 8(x − 2), which gives (x − 4)² = 0. Thus x = 4, the choice stating x is equal to 4.

AI-written and checked against the verified answer.

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