You are Here: Home >< Maths

# How to add/subtract two algebraic fractions with common denominators?

Announcements Posted on
Would YOU be put off a uni with a high crime rate? First 50 to have their say get a £5 Amazon voucher! 27-10-2016
1. Such as:

8/(x-5)(x+7) - 1/(x-5)(x-2)

Title is worded slightly stupidly.

How to add/subtract two algebraic fractions with common factors
2. The denominator remains the same, you just subtract/add the top numbers. So in this case it's 8 - 7.

Just think if I had 3/4 and took 1/4, I'd have 2/4 left.

EDIT: Ignore that, just realised the second bracket was different. Do cross multiplication to get rid of the thing that isn't common.
3. (Original post by BTAnonymous)
Such as:

8/(x-5)(x+7) - 1/(x-5)(x-2)
Same way as you would for a normal number one.

Like:

.

Here it's just:

4. (Original post by Zacken)
Same way as you would for a normal number one.

Like:

.

Here it's just:

Excellent! Thank you again!
5. (Original post by BTAnonymous)
Excellent! Thank you again!
No problem!

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
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
1. Oops, you need to agree to our Ts&Cs to register

Updated: May 16, 2016
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:
Today on TSR

### University open days

Is it worth going? Find out here

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams