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# Surd Question Watch

1. I first simplify the root75 to 5root3.
Rationalise the second to 9root3 over 3.
Simplify root12 into 2root3

5root3 - 9root3 / 3 + 2root3 .

Multiply through by the denominator of 3 to give:
15root3 - 9root3 + 6root3 = 10root3.

2. I think the answer is 4root3 , there isn't a mark scheme available which is why I'm not sure .
3. I did the question before looking at how you did it.

I had the same up until - "Multiply through by the denominator of 3"

At the point I simply did 9root3/3=3root3 (ie. Just the 9 divided by 3)

So I ended up with:
5root3 - 3root3 + 2root3 = 4root3

Thats what I would have done - is that the correct answer?
4. The answer is 4root3 !
5. Oh I forgot I could do that to the denominator, I thought I had to get rid of it somehow.

Yeah thats right thanks =)

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