How do you evaluate #Log 4 – log 400,000#? Precalculus Properties of Logarithmic Functions Common Logs 1 Answer A. S. Adikesavan Jun 2, 2016 #-5# Explanation: Use #log ab = log a + log b, log a^n = n log a and log 10 =1# Here, #log 4 - log 200000=log 4 - log(4X 100000)# #=log 4 - (log 4 + log !0^5)# #= -5 log 10 = -5 (1) = -5# Answer link Related questions What is the common logarithm of 10? How do I find the common logarithm of a number? What is a common logarithm or common log? What are common mistakes students make with common log? How do I find the common logarithm of 589,000? How do I find the number whose common logarithm is 2.6025? What is the common logarithm of 54.29? What is the value of the common logarithm log 10,000? What is #log_10 10#? How do I work in #log_10# in Excel? See all questions in Common Logs Impact of this question 4919 views around the world You can reuse this answer Creative Commons License