Answer:
x = 4
Explanation:
You want the solution(s) to log₈(2x) +log₈(x-3) = 1.
Domain
The log function is only defined for positive arguments, so the domain of this equation is ...
x - 3 > 0
x > 3
Only one answer choice is in this domain: x = 4.
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Additional comment
Trying this value in the equation gives ...
log₈(2·4) +log₈(4-3) = log₈(8) +log₈(1) = 1 + 0 = 1
so x = 4 is the solution.