You are Here: Home

# Stuck on a VERY simple question?!

Maths and statistics discussion, revision, exam and homework help.

Announcements Posted on
Important: please read these guidelines before posting about practical exams on The Student Room 26-11-2013
1. Stuck on a VERY simple question?!
Been bugging me for the last hour lol, I dont know if I'm missing anything out.

Factorise: 2x² - x - 3

After a google search I know the answer (which i wont reveal because I dont know how to spoiler) but I dont understand.

From my knowledge you times the coefficient of x² (2) by -3 = -6
Now find two numbers that:
(a) multiply to make -6 and
(b) add/subtract to make -1 (for -x ofc)

This seems impossible to me

Any help with steps would be appreciated!
2. Re: Stuck on a VERY simple question?!
-3 and +2?
3. Re: Stuck on a VERY simple question?!
(Original post by Idle)
-3 and +2?
Oh yh, ****
Last edited by Groat; 25-09-2012 at 23:30.
4. Stuck on a VERY simple question?!
2x^2-x-3

(2x+3)(x-2) = 0

X = 2 or -1.5

I don't know if this is completely wrong but I think the first part is right, I don't know where it goes after that

This was posted from The Student Room's iPhone/iPad App
5. Re: Stuck on a VERY simple question?!
You need to get a proper calculator. You don't have to work this out in the exams.

-3 * +2 = -6
-3 + 2 = -1
6. Stuck on a VERY simple question?!
Ooh no wait that 2 is a one

This was posted from The Student Room's iPhone/iPad App
7. Re: Stuck on a VERY simple question?!
How dyou factorise 2x^2 -3x +2x -3 then please?
8. Stuck on a VERY simple question?!
And the + and - are the other way round. Gah ignore me I made a mess haha D

This was posted from The Student Room's iPhone/iPad App
9. Stuck on a VERY simple question?!
(Original post by 23six)
How dyou factorise 2x^2 -3x +2x -3 then please?
It's the same
-3x +2x = -x

This was posted from The Student Room's iPhone/iPad App
10. Re: Stuck on a VERY simple question?!
(Original post by 23six)
How dyou factorise 2x^2 -3x +2x -3 then please?
2x(x+1) -3(x+1)

(2x-3) (x+1)

EDIT: Rearranged the twos and 3s together to get a common factor (x+1) then put the two numbers outside the brackets into a separate one alongside it.
Last edited by Robbie242; 25-09-2012 at 22:04.
11. Re: Stuck on a VERY simple question?!
(Original post by 23six)
How dyou factorise 2x^2 -3x +2x -3 then please?

Edit: Beat
12. Re: Stuck on a VERY simple question?!
(Original post by mimx)

Edit: Beat
Aww only by a few seconds! ^^
13. Re: Stuck on a VERY simple question?!
Thanks guys! I see where I confused myself now. Put the +2x -3x the other way around making it all weird
14. Re: Stuck on a VERY simple question?!
X1 = 1.5 X2 = -1

I other words: (2x-3) (x+1)

## Step 2: Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank

this is what you'll be called on TSR

2. this can't be left blank

never shared and never spammed

3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
your full birthday is required
1. By completing the slider below you agree to The Student Room's terms & conditions and site rules

2. Slide the button to the right to create your account

You don't slide that way? No problem.

Last updated: September 25, 2012
Study resources