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Fraction with Surds Question

Hello,

I have a question about problems like these. Here is the question

√23-√37 / √23+√37

I multiplied the denominator by √23-√37 which after simplifying gave me:

60-2√851 / -14

In this instance, as the denominator is negative, should I multiply by -1 and then divide by 2 to leave me with:

√851-30 / 7

Or shouldn't I have multiplied by -1, leaving the denominator as a negative? Your help is greatly appreciated!
Reply 1
I don't think it really matters.
Reply 2
Original post by L'Etudiant
Hello,

I have a question about problems like these. Here is the question

√23-√37 / √23+√37

I multiplied the denominator by √23-√37 which after simplifying gave me:

60-2√851 / -14

In this instance, as the denominator is negative, should I multiply by -1 and then divide by 2 to leave me with:

√851-30 / 7

Or shouldn't I have multiplied by -1, leaving the denominator as a negative? Your help is greatly appreciated!



What you did was correct
Reply 3
Original post by zed963
I don't think it really matters.


In what context would it not matter?
Reply 4
Original post by zed963
I don't think it really matters.


Original post by TenOfThem
What you did was correct


Okay, thanks guys! :biggrin:
Reply 5
Original post by TenOfThem
In what context would it not matter?


Well erm let see.

If you apply the negative to the numerator you still end up with a negative and if you apply it to the denominator it is still a negative so as long as you have the negative sign you should get the same answer if you put it into a calculator.

That's my theory.
Reply 6
Original post by zed963
Well erm let see.

If you apply the negative to the numerator you still end up with a negative and if you apply it to the denominator it is still a negative so as long as you have the negative sign you should get the same answer if you put it into a calculator.

That's my theory.


I see, interesting
Reply 7
Original post by TenOfThem
I see, interesting


I've no idea if it is right, do you know?
Reply 8
Original post by zed963
I've no idea if it is right, do you know?


Do I know what?

The OP was correct to change the denominator to a positive, as I said
Reply 9
Original post by TenOfThem
Do I know what?

The OP was correct to change the denominator to a positive, as I said


Never mind, do they always like the denominator to be +ve?
Original post by zed963
Never mind, do they always like the denominator to be +ve?


Who are they - the examiners?

They will not mark it incorrect if you leave it as a negative anymore than they would worry if you left a fraction un-cancelled

Unless they asked for simplest form

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