You are Here: Home >< Maths

# Surds help watch

1. Hi

Can anyone help with the following:

(2+√2)(3+√5)(√5-2)
(√5-1)(1+√2)

I have managed to get to the following but not sure what to do from here:

2√5 – 2 + √10 + √50 - 6√2
√5 + √10 - 1 - √2

Thanks
2. (Original post by Flutegirl02)
Hi

Can anyone help with the following:

(2+√2)(3+√5)(√5-2)
(√5-1)(1+√2)

I have managed to get to the following but not sure what to do from here:

2√5 – 2 + √10 + √50 - 6√2
√5 + √10 - 1 - √2

Thanks
What is your objective? If it's to rationalise the denominator then just multiply your fraction by before you expand the brackets.
3. Thanks. Yeah it's rationalising. I'll have a go tomorrow.
4. The trick is to keep the denominator factorised, at least until you have done the 'multiply top and bottom by this' trick.

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: September 7, 2016
Today on TSR

### Struggling to get going with your revision?

Get going with the all day revision thread

### Uni strikes! How do they affect you?

Discussions on TSR

• Latest
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

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE