Factorise x^2-x-6=0, and solve, finding the values of x

When you factorise an equation, the final form should look like this: (x+a)(a+b)=0 in order to work out the possible value(s) for x. As a result, working backwards, we expand the already factorised final form into x^2+ax+bx+ab=0. As this is a generalised form, we can use this to work out the factorised form of x^2-x-6=0. Therefore, ab has to equal -6. Consequently, ax+bx=-1x. This tells us that a+b=-1. We now have to different equations that can help us to work out what the values of a and b are, as the values of a and b need to give -6 when multiplied together, as well as give the answer of -1 when added together. Going through the possible values that a/b may have, we find that -3 and 2 work, as (-3)(2)=-6, and (-3)+(2)=-1. This, therefore, gives us the answer to the first part of the question. The factorised form of x^2-x-6=0 is (x-3)(x+2)=0. To answer the next part of the question, we use this factorised form. We know that anything multiplied by 0 gives the answer 0. Therefore, as the result of this equation is given to equal to 0, we know that either x-3, or x+2, have to give the value of 0. We can now make two separate equations, x-3=0, and x+2=0. This gives us the values of x to be 3, and -2, and hence we have solved the problem.

LS
Answered by Lior S. Maths tutor

8039 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations to find the values of x and y: 3x + 5y = -4 and 10x - 4y = -34


Solve the simultaneous equations (with a calculator)


The number of uniform spherical shots that can be made from a given mass of lead varies inversely to the cube of the radius. When the radius is 1mm the number of shots made is 2744. How many shots of radius 1.4mm can be made from the same mass.


Q: How to solve the simultaneous equations 3x+2y=7 and 5x+y=14


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:

© 2026 by IXL Learning