(x+y)(x-y)

The expression \((x+y)(x-y)\) can be simplified using the difference of squares formula. The formula states that:

\[ (a + b)(a - b) = a^2 - b^2 \]

In this case, let \(a = x\) and \(b = y\). Applying the formula gives us:

\[ (x+y)(x-y) = x^2 - y^2 \]

Therefore, the simplified result is:

\[ x^2 - y^2 \]