Solve the equation: log5 (4x+3)−log5 (x−1)=2.

As both terms on the left hand side have base 5 we know we can combine them. When dealing with logs, a minus means we can divide them, and a plus means we can multiply them. This will leave us with log5(4x+3/x-1)=2. Next we can get rid of the log, we do this by taking 5 squared as this is what the log means. This leaves us with 4x+3/x-1=5^2=25. We can now solve this to find x. 4x+3=25(x-1), expand the brackets: 4x+3=25x-25. Taking all x to one side and constants to the other leaves us with 28=21x. Therefore x=4/3

HG
Answered by Hugh G. Maths tutor

8419 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Use integration by parts to integrate the following function: x.sin(7x) dx


A straight line passes through the point (2,1) and has a gradient of 3. Find the co-ordinates of the points where this line intersects the axes


Use the binomial series to find the expansion of 1/(2+5x)^3 in ascending powers of x up to x^3 (|x|<2/5)


How do I solve a cubic?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences