You will also need to know how to rationalise a fraction. In this tutorial you are shown what rationalising a fraction is and how to do it for one term and two terms in the denominator. This method is often used to simplify a fraction that has a surd in the denominator.

#### Examples in the video

Rationalise the following:

RowanSeptember 22, 2016 at 3:06 pmI have a question: wouldn’t we use an identical sign (3 dashes) here? I know many people use the equal sign all the time, but an identical sign would be more correct HERE, right?

Stuart SiddersSeptember 22, 2016 at 4:21 pmNot really as it is not an algebraic expression, this is numerical and has one value.

BillSeptember 28, 2016 at 4:57 pmFor question 4, could I just leave my answer as 15root2/7 ??

Stuart SiddersSeptember 28, 2016 at 6:20 pmNo, but if you expand the brackets then this will give (15 + 5root2)/7

hajerOctober 3, 2016 at 7:16 pmuno this work do we do it in year 10?

coz i proper don’t understand so its quiet a shame….

CallumNovember 3, 2016 at 10:40 pmIn question 4, why do we change the minus to a plus to multiply by 3+root2 over 3+root2? Why doesnt it work keeping it as a minus?

JasonNovember 10, 2016 at 3:09 pmI think its so that the two rooted terms you get from the multiplication cancel each other out, leaving you with just the number terms behind. might be wrong tho??

SophiaDecember 13, 2016 at 6:44 pmIt is to cancel out the -3 root 2 and +3 root 2, so you are left with a number and a square root number