Factorise fully 12x^2-20x+3

By factorising we're attempting to simplify this expression. When we factorise quadratics, typically this will result in two brackets. The content of these brackets, can be simply worked out with trial and error. I like to start by writing a list of pairs of factors for 12 and also 3. (12 and 1, -12 and -1, 6 and 2, -6 and -2, 3 and 4, -3 and -4) (3 and 1, -3 and -1). Now use trial and error to work out which two pairs multiplied with each other, and then added together make -20. In this case it is ( -6 and -2) as well as (3 and 1) since 3x-6=-18 and 1x-2=-2, and then -18+-2= -20. Now you just place these in the form (ax+b)(cx+d), ensuring that the placements are correct so that the right numbers are multiplying. i.e. with the same numbers your two brackets could expand to make a completely different quadratic. Eg. (-6x+3)(-2x+1) expands to make 12x^2-12x+3. Therefore the correct factorisation is (-6x+1)(-2x+3)

SO
Answered by Santiago O. Maths tutor

4391 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Out of a sample of 80 batteries, 3 are faulty. What percentage of the batteries are faulty?


ABC is a right angled triangle. D is the point on AB such that AD = 3DB. AC = 2DB and angle A = 90 degrees. Show that sinC = k/√20 where k is an integer. Find the value of k


How do I use the quadratic formula?


Find the Lowest common multiple of 96 and 132


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:

© 2025 by IXL Learning