ln(xy²/z)
Three rules of logarithms apply:
... ln(xy) = ln(x) + ln(y)
... ln(x/y) = ln(x) - ln(y)
... ln(x^y) = y·ln(x)
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Using these, we find that your sum of logarithms can be written as the log of the product ...
... ln(x) +2ln(y) -ln(z) = ln(x) + ln(y²) - ln(z) = ln(xy²/z)