Factorise fully 27x^2 - 3

First, work out what number is a common factor of both terms - in other words what number 'goes into' both 27 and 3? 3 is a factor of both so put 3 outside the bracket. = 3( __ - __) Now work out what goes in each of the gaps inside the bracket - what do you need to multiply by 3 to get 27x2 ? What about to get - 3 ? = 3(9x2-1) But make sure you don't stop there! We need to factorise the expression inside the bracket, to make sure we have done what the exam question asked and factorised 'fully'. You may recognise that this expression looks familiar - it is the difference of 2 squares because there is no x term, only an x2 and a number. So we know the factorised version must look like this: =3(_x + _)(_x - _) To find the missing numbers we just need to work out what multiplies by itself to make 9 & what multiplies by itself to make 1. = 3(3x+1)(3x-1)

Answered by Rebecca T. Maths tutor

3350 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Daniel and Mohammed buy concert tickets for £63. All the concert tickets are the same price. Daniel pays £24.50 for 7 tickets. How many tickets does Mohammed buy? .


The equation of the line L1 is: y = 5x-4. The equation for line L2 is 2y-10x+16 = 0. Show that these two lines are parallel.


There are n sweets in a bag, 6 orange, rest yellow. H takes two, one after another, and eats them. Probability both are orange is 1/3. Show n^2 - n - 90 = 0.


If f(x) = 2x+5, g(x) = 8x-7 and f(x)=g(x). Find the value of x. Show your working.


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