Factorise x^2-x-12

To factorise this equation we want to get 2 brackets. We are looking for 2 numbers which multiply to make -12 and add to make -1. So, let's see some factors of -12: -12 = (-1) x 12; (-2) x 6; (-3) x 4; (-4) x 3; here we can see that -4 & 3 add to make -1 and since they are also factors of -12, this pair fills the criteria. So, the factorisation of x2-x-12 = (x-4)(x+3).To check if you factorised the equation correctly, we can expand the brackets to get: x2-4x+3x-12 which = x2-x-12 so we know our values of -4 and 3 are definitely correct.

FA
Answered by Fizza A. Maths tutor

20028 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Expand and simplify (x – 2)(2x + 3)


OCR, 2016, Higher Maths: Rationalise the denominator 1/(1+sqrt(3))


Simplify (2^2)^3


How do you factorise a quadratic with a co-efficient in front of the x^2 - e.g: 3x^2 + 14x + 8


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