How do you solve #e^ { - 4x } + 8= 35#? Precalculus Properties of Logarithmic Functions Logarithm-- Inverse of an Exponential Function 1 Answer Paramecium · Stefan V. May 18, 2017 You have to use logarithms. Explanation: #e^(-4x) + 8 = 35# #e^(-4x) = 27# #ln 27 = - 4x# #(ln 27) / (-4) = x# #"*"ln# is basically #log_e# #x# is approximately #-0.8240#. Answer link Related questions What is a logarithm? What are common mistakes students make with logarithms? How can a logarithmic equation be solved by graphing? How can I calculate a logarithm without a calculator? How can logarithms be used to solve exponential equations? How do logarithmic functions work? What is the logarithm of a negative number? What is the logarithm of zero? How do I find the logarithm #log_(1/4) 1/64#? How do I find the logarithm #log_(2/3)(8/27)#? See all questions in Logarithm-- Inverse of an Exponential Function Impact of this question 1760 views around the world You can reuse this answer Creative Commons License