Solving Radical Equations: Multiplying and Simplifying Roots

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    Homework Radicals
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To solve the expression (√3 + √5)(√3 - √6), the correct approach involves using the distributive property to multiply each term. The result simplifies to √3² - √3√6 + √5√3 - √5√6. However, the final numerical approximation of -2.846882916 is not considered an accurate representation due to the presence of surds. The discussion emphasizes the importance of maintaining exact values rather than approximating them. Understanding how to properly handle radical expressions is crucial for accurate solutions.
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Homework Statement



(square root of 3 + square root of 5)(square root of 3-square root of6)

Homework Equations





The Attempt at a Solution


Im confused on what to multiply what with.
 
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How would you multiply (x + y)(x - z) out?

The Bob
 


I don't know but that's what I've gotten :
(\sqrt{3}+\sqrt{5})(\sqrt{3}-\sqrt{6})=\sqrt{3}(\sqrt{3}-\sqrt{6})+\sqrt{5}(\sqrt{3}-\sqrt{6})=\\<br /> \sqrt{3}\cdot\sqrt{3}-\sqrt{3}\cdot\sqrt{6}+\sqrt{5}\cdot\sqrt{3}-\sqrt{5}\cdot\sqrt{6}=\\<br /> =-2.846882916
 


Well that is a way to do it but you've not produced an 'accurate' answer by using surds. As this has been posted, Stratosphere what would you have done?

The Bob
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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