How do I solve the following question. 'Find the values of x such that 2log3(x) - log3(x-2) = 2'.

How do I solve the following question. 'Find the values of x such that 2log3(x) - log3(x-2) = 2'.To simplify this equation in order to solve it, the first step is to simplify the 2log3x term. The log rule 'n.logb(m) = logb(m)n' will enable us to do this. Using this rule makes the equation: log3(x2) - log3(x-2) = 2. The next step is to recognise that the equation can be simplified by using another log rule 'logb(m) - logb(n) = logb(m/n)'. So by applying this rule to our equation we end up with log3(x2/(x-2)) = 2. Our equation is now made up of just two terms. Logarithms are just another way of writing indices. If a = bcthen c = logba . In our equation a = (x2/(x-2)), b = 3 and c = 2, by substituting these values into a = bc, you get (x2/(x-2)) = 32.Now this expression can be rearranged into a quadratic equation, which can then be solved. The steps for this are shown below:(x2/(x-2)) = 9 x2 = 9(x-2) x2= 9x -18 x2- 9x + 18 = 0 x2- 9x +18 = 0 (x-6)(x-3)=0 x=3, x=6

LR
Answered by Lauren R. Maths tutor

17325 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the two simultaneous equations X2 +2Y2= 18 and X - Y = 3


Write 7.264 51 correct to 3 decimal places.


Solve 2x-5=3x+4


In the isosceles triangle ABC, AB=AC and angle B=(3x +32)degrees and angle C=(87-2X)degrees


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning