Find Solution to x^2 + x - 2=0

Using the factorisation method.

the factorised solution will look like (x+a)(x+b) = 0

by multiplying these two brackets we get the equation:

x^2 + a.x+b.x + a.b = 0

so vomparing this to the equation in the question we see

a.b = -2        and       a+b = 1    and   a = -2/b

using substitution:

b^2 - 2 = b

b(b-1) = 2      so     b=2   (try substituting this in)

if b = 2 then a = -1

so the solution is 

(x - 1)(x + 2) = 0

Matthew P. 11 Plus Maths tutor, GCSE Maths tutor, A Level Maths tutor...

4 months ago

Answered by Matthew, a GCSE Maths tutor with MyTutor

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


£18 /hr

Roshni R.

Degree: Dentistry (Bachelors) - Birmingham University

Subjects offered: Maths, Spanish+ 4 more

-Personal Statements-
-Medical School Preparation-

“Tutoring approach Professional but friendly approach.  Work with my students to identify the areas the student is finding most difficult. Review the topic with my hand-written notes.  Explain any misunderstood areas. Work through examp...”

£18 /hr

Kim N.

Degree: Classics (Bachelors) - Durham University

Subjects offered: Maths, Latin+ 1 more

Classical Greek

“ABOUT ME: Hello! I'm Kim and am currently doing Classics at Durham. I was always interested in languages and the culture and history behind it, which means even now I'm trying to learn new languages and their culture! Ancient Greece a...”

£22 /hr

Emma M.

Degree: Natural Sciences (Bachelors) - Durham University

Subjects offered: Maths, Psychology


“ I am currently studying Natural Sciences (Maths and Psychology) at Durham University. I have had a passion for Maths and Psychology since the moment I started studying them and am keen toshare my enthusiasm for these subject through ...”

About the author

Matthew P.

Currently unavailable: for new students

Degree: Electronic & Electrical Engineering (Bachelors) - Southampton University

Subjects offered: Maths, Physics+ 1 more


“About me: I'm an undergarduate Electronic Engineer studying at the University of Southampton. I really enjoy working on new projects, such as designing robots and other rasberry pi projects, and it stems from a love of Physics and Mat...”

MyTutor guarantee

You may also like...

Posts by Matthew

Convert the decimal number 165 to binary

Explain the difference between forced vibration and resonance in an oscillating object.

find general solution to: x(dy/dx) + 2y = 4x^2

Find Solution to x^2 + x - 2=0

Other GCSE Maths questions

How does one find the highest common factor (HCF) and lowest common multiple (LCM) of 36 and 48?

What is compound interest and how do I calculate it?

When I multiple two negative numbers together is my answer positive or negative?

How do I factorise a quadratic equation?

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