(√7-√5)(√7+√5)

To simplify the expression \((\sqrt{7} - \sqrt{5})(\sqrt{7} + \sqrt{5})\), you can use the difference of squares formula, which states that \((a-b)(a+b) = a^2 - b^2\).

Here, let:

• \( a = \sqrt{7} \)
• \( b = \sqrt{5} \)

Now, apply the formula:

\[ (\sqrt{7} - \sqrt{5})(\sqrt{7} + \sqrt{5}) = a^2 - b^2 \]

Calculating \( a^2 \) and \( b^2 \):

\[ a^2 = (\sqrt{7})^2 = 7 \] \[ b^2 = (\sqrt{5})^2 = 5 \]

Now substitute these back into the expression:

\[ a^2 - b^2 = 7 - 5 = 2 \]

Thus, the simplified result is:

\[ \boxed{2} \]