(√2-√5)*(√2+√5)

To simplify the expression \((\sqrt{2} - \sqrt{5})(\sqrt{2} + \sqrt{5})\), we can use the difference of squares formula, which states that \((a - b)(a + b) = a^2 - b^2\).

In this case, we let \(a = \sqrt{2}\) and \(b = \sqrt{5}\).

Now we apply the formula:

\[ (\sqrt{2})^2 - (\sqrt{5})^2 = 2 - 5 = -3 \]

Therefore, the simplified result of \((\sqrt{2} - \sqrt{5})(\sqrt{2} + \sqrt{5})\) is \(-3\).