Simplify the radical expression.

(8 + √11)(8 - √11)

Using the difference of squares formula, we get:

(8 + √11)(8 - √11) = 8^2 - (√11)^2 = 64 - 11 = 53

Therefore, the simplified radical expression is √53.

To simplify the given radical expression (8 + √11)(8 - √11), we can use the difference of squares formula, which states that (a + b)(a - b) = a^2 - b^2.

In this case, a = 8 and b = √11.

So, applying the formula, we have:

(8 + √11)(8 - √11) = 8^2 - (√11)^2

Simplifying further:

= 64 - 11

= 53

Therefore, the simplified radical expression is 53.