25×2 - 121y2

This expression cannot be simplified further without knowing more information or a specific operation to perform on it.

To simplify the expression 25×2 - 121y2, let's break it down step by step:

Step 1: Simplify the square of 25.
25 × 2 - 121y2 becomes 50 - 121y2.

Step 2: Simplify the square of y.
The expression remains the same, so it becomes 50 - 121y2.

Therefore, the simplified expression is 50 - 121y2.