How do you simplify #ln 3 − 2 ln 9 + ln 18 #? Precalculus Properties of Logarithmic Functions Natural Logs 1 Answer George C. Sep 1, 2015 #ln 3 - 2 ln 9 + ln 18 = ln (2/3) = ln 2 - ln 3# Explanation: Use:#color(white)(XX)ln a + ln b = ln (ab)# and:#color(white)(XX)ln a - ln b = ln (a/b)# to simplify: #ln 3 - 2 ln 9 + ln 18# #=ln 3 + ln 18 - ln 9^2# #=ln (3*18) - ln 81# #=ln 54 - ln 81# #=ln (54/81)# #=ln (2/3)# #=ln 2 - ln 3# Answer link Related questions What is the natural log of e? What is the natural log of 2? How do I do natural logs on a TI-83? How do I find the natural log of a fraction? What is the natural log of 1? What is the natural log of infinity? Can I find the natural log of a negative number? How do I find a natural log without a calculator? How do I find the natural log of a given number by using a calculator? How do I do natural logs on a TI-84? See all questions in Natural Logs Impact of this question 8491 views around the world You can reuse this answer Creative Commons License