How do you solve 4^(x +4) = 5^((2x)/ 5)? Precalculus Solving Exponential and Logarithmic Equations Logarithmic Models 1 Answer Bdub Apr 21, 2016 x=(4ln4)/(ln4-2/5 ln5)~~7.47 Explanation: ln 4^(x+4)=ln 5^(2/5 x) (x+4)ln4=2/5 xln5 xln4+4ln4-2/5 x ln5=0 xln4-2/5 x ln5=4ln 4 x(ln4-2/5 ln5)=4ln4 x=(4ln4)/(ln4-2/5 ln5)~~7.47 Answer link Related questions What is a logarithmic model? How do I use a logarithmic model to solve applications? What is the advantage of a logarithmic model? How does the Richter scale measure magnitude? What is the range of the Richter scale? How do you solve 9^(x-4)=81? How do you solve logx+log(x+15)=2? How do you solve the equation 2 log4(x + 7)-log4(16) = 2? How do you solve 2 log x^4 = 16? How do you solve 2+log_3(2x+5)-log_3x=4? See all questions in Logarithmic Models Impact of this question 3592 views around the world You can reuse this answer Creative Commons License