x Turn on thread page Beta
 You are Here: Home >< Maths

# hard factoring question watch

1. Hi

can someone help me with factorising the following:

x^2 + yx - 2y^2
2. (Original post by hajs)
Hi

can someone help me with factorising the following:

x^2 + yx - 2y^2
think about 2 brackets with x and y in them
3. (Original post by TeeEm)
think about 2 brackets with x and y in them
Hi!

Im trying but I cant see it, is there another method i can apply or i this more about trying to see which numbers can be placed into brackets?
4. (Original post by hajs)
Hi!

Im trying but I cant see it, is there another method i can apply or i this more about trying to see which numbers can be placed into brackets?
(x ? y)(x ? 2y)

any good
5. (Original post by TeeEm)
(x ? y)(x ? 2y)

any good
oooh, okay, yeah thank you!!

but how would you just know that straight away? ahha.
6. (Original post by hajs)
oooh, okay, yeah thank you!!

but how would you just know that straight away? ahha.
practice
7. (Original post by hajs)
Hi

can someone help me with factorising the following:

x^2 + yx - 2y^2
The quadratic will factorise into 2 brackets just like any other. It does seem intimidating that there's a y^2 but if you treat it like any other constant you can see that it will factorise quite well. If you need any help let me know and please rep me .

Thanks x
8. Just treat it like a normal quadratic.
Give two numbers (i.e. expressions in terms of y) that multiply to give -2y² and add to give y.
9. (Original post by hajs)
oooh, okay, yeah thank you!!

but how would you just know that straight away? ahha.
He's good like that
10. (Original post by hajs)
Hi

can someone help me with factorising the following:

x^2 + yx - 2y^2
You could do it this way:

Just like a normal quadratic, you're looking for two expressions that multiply to give and add to give .

For there aren't too many choices and some combination of and with chosen signs looks to be the way to go. It then shouldn't be too hard to spot which to use.

EDIT : Sorry Razzor - didn't notice your post

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: February 20, 2016
Today on TSR

### Is uni even worth it?

Does anyone use their degree?

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams