718 views

### Surd Calculations?

Surds are numbers left in 'square root form' (or 'cube root form' etc). They are therefore irrational numbers. Surds are the root of numbers and not whole numbers.

Multiplication

Example:

√2 × √6 = √12 (= 2× 6)

= √4 × √3

= 2√3

4√3 - 2√3 = 2√3

5√5 + 8√5 = 13√5

Note: 5√7 + 3√3 cannot be manipulated because the surds are different (one is √7 and one is √3)

Example:

Simplify √12 + √27

12 = 3 × 4. So √12 = √(3 × 4) = √3 × √4 = 2 × √3.

Similarly, √27 = 3√3.

Hence √12 + √27 = 2√3 + 3√3 = 5√3

2 years ago

Answered by Nita, a GCSE Maths tutor with MyTutor

## Still stuck? Get one-to-one help from a personally interviewed subject specialist

#### 618 SUBJECT SPECIALISTS

£20 /hr

Degree: Mathematics (Masters) - Bath University

Subjects offered:Maths, Geography+ 1 more

Maths
Geography
-Personal Statements-

“Hi! I'm Kate. I'm a mathematics student who strives to improve students confidence, enjoyment and ability in mathematics and geography.”

£18 /hr

Degree: Medicine (Bachelors) - Cambridge University

Subjects offered:Maths, Chemistry+ 4 more

Maths
Chemistry
Biology
-Personal Statements-
-Oxbridge Preparation-
-Medical School Preparation-

“A friendly medical student at Cambridge. Experienced and motivated to share knowledge of sciences, medical school and Oxbridge application.”

£22 /hr

Degree: Medicine (Bachelors) - Edinburgh University

Subjects offered:Maths, Chemistry+ 3 more

Maths
Chemistry
Biology
-Personal Statements-
-Medical School Preparation-

“Hi, I'm a first year medic at Edinburgh. I've had 7 years' worth of experience teaching children Maths and English and have mentored lower school peers, so I'm bound to have an approach that will suit your learning style!”

Currently unavailable:

Degree: BSc Accounting and Finance (Bachelors) - Bristol University

Subjects offered:Maths

Maths

“Hi! I'm Nita, second year Accounting and Finance student at the University of Bristol. I am keen on sharing my experiences and help out in Maths at GCSE level. ”

MyTutor guarantee

### You may also like...

#### Other GCSE Maths questions

Make y the subject of (y/x)+(2y/(x+4))=3

Can you make 'p' the subject of the following equation? 4(p-2q)= 3p+2

Insert one pair of brackets so that this calculation is correct; 3 x 6 + 5 - 1 = 32

3 postitive whole numbers have a mean of 6. What is the greatest possible range of the numbers?

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this.