1. Mar 3, 2009

Stratosphere

1. The problem statement, all variables and given/known data

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

2. Relevant equations

3. The attempt at a solution
Im confused on what to multiply what with.

2. Mar 3, 2009

The Bob

How would you multiply (x + y)(x - z) out?

The Bob

3. Mar 3, 2009

boaz

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

4. Mar 3, 2009