Victoria V. answered • 05/20/20

15+ Years Experience Teaching / Tutoring Trigonometry

This is very unclear the way it is typed, but the only way it makes sense (and is true) is if I rewrite it as:

log_{x}(xy) - 2 log_{x}(y) = 1 - log_{x}(y)

Properties of logs say we can expand:

log_{x}(x) + log_{x}(y) - 2 log_{x}(y)

By definition, log_{x}(x) = 1

So this becomes 1 + log_{x}(y) - 2 log_{x}(y) and this becomes 1 - log_{x}(y)