How do I solve a quadratic equation?

The best way to solve a quadratic function is to put brackets into the equation.

Start with an example

Find x when y=0 for the function 

y=x*2 + 5x + 6

As y=0 make the whole equation= 0:

x*2 + 5x + 6=0

Try and put this into brackets:

(x+a)(x+b)=0 (as all the values are positive, we know that there are going to be no negative signs in the brackets).

Now we just need to find values for a and b that multiply out to give us the equation we need.

Try a=6 and b=1:

This gives us the 6 at the end but when multiplied out gives us 7x- which is too much.

Now try a=2 and b=3 and multply out:

We get 0=x2+ 2x + 3x + 6= x2 + 5x + 6 ... which is what we want!

So we get (x+2)(x+3)=0

For it to equal 0 either:

x+2=0 so x=-2 or

x+3=0 so x=-3

so x=-2, -3

Answered by Rosiered B. Maths tutor

3629 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

3 teas and 2 coffees have a total cost of £7.80 5 teas and 4 coffees have a total cost of £14.20 Work out the cost of one tea and the cost of one coffee.


A price is decreased by 27% The new price is £1138.80 Work out the original price.


HIGHER TIER a) Factorise the following equation into two bracket form: 2x^2-5x-12. b)2x^2-5x-12=0. Solve this equation to find the values of x, using your answer to part a). BONUS c) Sketch the function y=2x^2-5x-12, showing any x intercepts


Solve: x^2-x-6 using factorisation.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences