Logarithm help needed

Answer:
The answer to your question is: log₇ ([tex]\frac{xy}{z}[/tex])
Step-by-step explanation:
log₇ x + log₇ y - log₇ z
First he must use the product rule that says:
log a x + log a y = log a xy
Then, he must use the quotient rule that says
log a x - log a y = log a ([tex]\frac{x}{y}[/tex]
He did not use these rules that's why his answer is incorrect.
The correct answer is:
log₇ (xy) - log₇ z
log₇ [tex]\frac{xy}{z}[/tex]