posted by Zac .
Express the given quantity in a single logarithm.
ln(a + b) + ln(a - b) - 2 ln c
The sum of two logarithms is equal to the logarithm of the product, and the difference equals the quotient:
Twice the logarithm of a quantity is the logarithm of the square of the quantity:
So if we put it all together, we get: