I got the answer to be 7 over 3 is that correct
thanks.
Algebraic Fraction
Announcements  Posted on  

Four things that unis think matter more than league tables  08122016 

 Follow
 1
 06052012 18:00

 Follow
 2
 06052012 18:09
No, that's not right. Post your working.

 Follow
 3
 06052012 18:14

 Follow
 4
 06052012 18:15
2x(x)7/x(2x3)x(2x3)
2x^27/2x^23
2x^2 cancels out so you're left with 7/3 
 Follow
 5
 06052012 18:16
(Original post by AtomSmasher)
I believe the answer is:
Post your working so we can see what the problem is.
I shouldn't have multiplied out the denominator. 
 Follow
 6
 06052012 18:19
Please let me know if you're not confident with this and I could explain further or give you some questions.Last edited by notnek; 06052012 at 18:21. 
 Follow
 7
 06052012 18:19
(Original post by zed963)
2x(x)7/x(2x3)x(2x3)
2x^27/2x^23
2x^2 cancels out so you're left with 7/3
Remember, you can only cancel out common factors and since isn't a factor you can't cancel it out. 
 Follow
 8
 06052012 18:22
(Original post by AtomSmasher)
I the denominator is meant to be .
Remember, you can only cancel out common factors and since isn't a factor you can't cancel it out. 
 Follow
 9
 06052012 18:23
(Original post by notnek)
You cannot cancel terms in a fraction, only factors. 2x^2 is not a factor of the numerator or the denominator.
Please let me know if you're not confident with this and I could explain further or give you some questions. 
 Follow
 10
 06052012 18:23
This is a very common misconception and it is terribly wrong. I suggest you take notnek up on his offer if you don't understand why your attempt doesn't work.

 Follow
 11
 06052012 18:30
(Original post by zed963)
Sure give me some questions.
e.g. 3xy+2x
The two terms here are 3xy and 2x.
A factor is something which is part of a product.
e.g. 3xy + 2x
In the first term, the factors are 3, x and y. And in the second term, the factors are 2 and x.
When cancelling algebraic fractions, you can only do it if the thing that you want to cancel is a factor of both the numerator and the denominator.
e.g.
x is a factor of the whole of the numerator and is also a factor of the denominator so you cancel it to get:
Next example:
There are two terms on the numerator, 2xy and 3. 2xy is not a factor of the numerator. 2xy is a factor of the denominator but it has to be a factor of both in order to cancel. So you would leave this fraction as it is.
Now try simplifying these fractions:
a)
b)
c)
d)
For d), try simplifying the numerator.Last edited by notnek; 06052012 at 19:50.Post rating:1 
 Follow
 12
 06052012 18:32
(Original post by zed963)
But if I expand the top I get 2x^2 and in the the denominator it is the same so why can't I cancel them out.
I'll just do a very simple example, it always helps: You can factorise to . Since 2x is a common factor you can cancel it out, getting . However, you can express the same fraction as , but since these are not factors, you can't cancel them out. If you tried cancelling them, you'd end up with , which obviously isn't the same.
Sorry if this seems like a kind of childish explanation, I'm sure you know what I mean though?Last edited by AtomSmasher; 06052012 at 18:34. 
 Follow
 13
 06052012 18:33
(Original post by notnek)
Ok first you must realise the difference between "terms" and "factors". A term is something in algebra which is separated from other things by either + or .
e.g. 3xy+2x
The two terms here are 3xy and 2x.
A factor is something which is part of a product.
e.g. 3xy + 2x
In the first term, the factors are 3, x and y. And in the second term, the factors are 2 and x.
When cancelling algebraic fractions, you can only do it if the thing that you want to cancel is a factor of both the numerator and the denominator.
e.g.
x is a factor of the whole of the numerator and is also a factor of the denominator so you cancel it to get:
Next example:
There are two terms on the numerator, 2xy and 3. 2xy is not a factor of the numerator. 2xy is a factor of the denominator but it has to be a factor of both in order to cancel. So you would leave this fraction as it is.
Now try simplifying these questions: 
 Follow
 14
 06052012 18:35
(Original post by AtomSmasher)
You can only cancel them out if they are factors, i.e., when multiplied by something else (not added or subtracted from) it makes the expression. You know all about factorising right?
I'll just do a very simple example, it always helps: You can factorise to . Since 2x is a common factor you can cancel it out, getting . However, you can express the same fraction as , but since these are not factors, you can't cancel them out. If you tried cancelling them, you'd end up with , which obviously isn't the same.
Sorry if this seems like a kind of childish explanation, I'm sure you know what I mean though? 
 Follow
 15
 06052012 18:39
(Original post by notnek)
Ok first you must realise the difference between "terms" and "factors". A term is something in algebra which is separated from other things by either + or .
e.g. 3xy+2x
The two terms here are 3xy and 2x.
A factor is something which is part of a product.
e.g. 3xy + 2x
In the first term, the factors are 3, x and y. And in the second term, the factors are 2 and x.
When cancelling algebraic fractions, you can only do it if the thing that you want to cancel is a factor of both the numerator and the denominator.
e.g.
x is a factor of the whole of the numerator and is also a factor of the denominator so you cancel it to get:
Next example:
There are two terms on the numerator, 2xy and 3. 2xy is not a factor of the numerator. 2xy is a factor of the denominator but it has to be a factor of both in order to cancel. So you would leave this fraction as it is.
Now try simplifying these fractions:
a)
b)
c)
d)
For d), try factorising the numerator.
b) 3xLast edited by zed963; 06052012 at 18:47. 
 Follow
 16
 06052012 18:43
(Original post by zed963)
For a) 3x+15/2(x+2) 
 Follow
 17
 06052012 18:48
(Original post by raheem94)
No, try again. 
 Follow
 18
 06052012 18:49
(Original post by zed963)
3x+15/2

 Follow
 19
 06052012 18:50

 Follow
 20
 06052012 18:50
(Original post by zed963)
3x+15/2
Write a reply…
Reply
Submit reply
Register
Thanks for posting! You just need to create an account in order to submit the post Already a member? Sign in
Oops, something wasn't right
please check the following:
Sign in
Not got an account? Sign up now
Updated: May 7, 2012
Share this discussion:
Tweet
Related discussions:
 C4 partial fraction
 Maths C3  Cancelling down Algebraic Fractions...Help with Q ...
 Algebraic LongDivision, where the divifing $x$ has a co ...
 Can this fraction be simplified further? (C1 Algebra)
 Algebraic fractions
 Help on this algebraic modelling question
 algebraic division  extension issue
 C3 Algebraic Fractions
 Core 4 Algebraic Fractions
 Algebraic Fractions
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.