With log base 4, solve log(2x+3) + log(2x+15) = 1 + log(14x+5)

How might one simplify this? It looks as though raising both sides to the power 4 is the way to go, but it is not immediately obvious how to do this. In order to get both sides into the form 'log of something', we need to apply log laws. A student familiar the log laws will see that we do this to the LHS by multiplying together the arguments. For the RHS, an additional step is required, to convert 1 into log(4) before doing this. (Note: it is only this step which makes the base of the log particularly relevant.) 

Once this has been done, and both sides raised to the power 4, it is simply a case of solving a quadratic, either by inspection (which is not terribly difficult), or using the quadratic formula.

Answered by Sam J. Maths tutor

3133 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

OCR M2 A level maths June 2015 question 8


What is the difference between differentiation and integration, and why do we need Calculus at all?


Integrate sin^2(x) with respect to x


Find the turning points of the curve y = 3x^4 - 8x^3 -3


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 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences