Maths question +REP

[Apolva]

Hey I'm stuck on this from a past paper:

Expand and simplify: (√3+√15)²

Give your answer in the form n+m√5, where n and m are integers.

Thanks

Geez, what exam board are you sitting? That's a bloody difficult question. Sorry I can't be of help!

[Kieran]

It's a long time since I've done any maths like this so forgive me if I'm wrong

(√3+√15)² = (√3+√15)(√3+√15)

Then you need to expand the brackets out. Doing so you get this:

√9 + √45 + √45 + √225

This then goes to

3 + 3√5 + 3√5 + 15

Which equals (18 + 6√5)

[Apolva]

Thanks a lot

+rep

[Kieran]

No problem

I remember doing those sort of questions.... memories

[alexxxxx]

it's all about binomial expansions these days gawsh.

[MattFr]

it's all about binomial expansions these days gawsh.

binomial expansions are ez, lern some moar math

[alexxxxx]

binomial expansions are ez, lern some moar math

did i say dey were ard m8?

[MattFr]

did i say dey were ard m8?

no m8, i didnt say you did