Hey, I'm really struggling with a question on my maths homework.

Express root5 +3/root 5 -2 in the form Proot5 + Q where P and Q are integers

I got 2root5

Is this right?

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- Sep 14th 2009, 10:31 AMmaplemattsurds
Hey, I'm really struggling with a question on my maths homework.

Express root5 +3/root 5 -2 in the form Proot5 + Q where P and Q are integers

I got 2root5

Is this right? - Sep 14th 2009, 11:18 AMe^(i*pi)
- Sep 14th 2009, 11:20 AMmaplematt
- Sep 14th 2009, 11:28 AMe^(i*pi)
I

*could*have misread the OP but I don't think so.

Let $\displaystyle u = \sqrt{5}$ so that the equation becomes $\displaystyle u + 3u - 2$

What I did was said that you can combine the u terms to give $\displaystyle 4u - 2$

And since $\displaystyle u = \sqrt{5}$ we get $\displaystyle 4\sqrt{5} - 2$

$\displaystyle 4$ and $\displaystyle -2$ are both integers so it does satisfy the terms - Sep 14th 2009, 11:31 AMmaplematt
- Sep 14th 2009, 11:39 AMmasters
- Sep 14th 2009, 11:45 AMe^(i*pi)