Factorise x² + 2x - 8

Since an x² is produced, we know that the factorised version will be (x+a)(x+b). To find a and b we need to consider the relationship between 2 and -8. It is going to be factorised into two brackets, due to the x², so we need to break the 2 down into 2 numbers that will add to give 2 and multiply together to give -8. The 8 is negative so one of these numbers must also be negative. These 2 numbers must be 4 and -2. Then substitude these numbers in to be a and b so the equation factorised is (x+4)(x-2)

Hannah B. 13 Plus  Maths tutor, GCSE Maths tutor, A Level Maths tutor...

2 months ago

Answered by Hannah, a GCSE Maths tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist


£18 /hr

Molly B.

Degree: Biology (Bachelors) - Bristol University

Subjects offered: Maths, Science+ 4 more

Human Biology
-Personal Statements-

“Who am I? I am a Biology student at the University of Bristol. I am a positive and friendly person and have always been enthusiastic to learn new things. I hope to pass this on to my students and that I will make learning fun by using...”

MyTutor guarantee

£18 /hr

Ellen K.

Degree: Modern Languages and Cultures (Other) - Durham University

Subjects offered: Maths, German+ 1 more


“Hi, I'm Ellen and I'm studying Modern Foreign Languages and Cultures at Durham University. I achieved 3 As in my A-Levels in Maths, French and German. I have lots of experience working with children as I volunteered for several years a...”

MyTutor guarantee

£18 /hr

Matthew S.

Degree: Economics (Bachelors) - Exeter University

Subjects offered: Maths, History+ 2 more

Extended Project Qualification

“Who am I? I am a 3rd Year Economics Student at the University of Exeter. Economics has always been at the top of my interests meaning that I have real passion for all things economics and math based which I will aim to instill into my...”

About the author

£18 /hr

Hannah B.

Degree: History (Bachelors) - Durham University

Subjects offered: Maths, History


“Top tutor from the renowned Russell university group, ready to help you improve your grades.”

MyTutor guarantee

You may also like...

Posts by Hannah

Factorise x² + 2x - 8

How do I analyse a primary source?

Solve the simultaneous equations 2x + y = 7 and 3x - y = 8.

Other GCSE Maths questions

Solve the simultaneous equations 4x + 7y = 1 and 3x +10y = 15.

How do I solve 7x – 8 = -3x + 2?

Solve x^2 + 4x + 4 = 0

How do I solve the quadratic equation x^2+4x+3=0

View GCSE Maths tutors


We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss