Which expression has a negative value?

To determine which expression has a negative value, we need to look at the signs of the products in each expression.

1. -2 · 4 · -6 · 8 · -10: There are three negative numbers (-2, -6, -10), which means the product will be negative (odd number of negative signs results in a negative product).

2. 2 · -4 · -6 · -8 · -10: There are three negative numbers (-4, -6, -8), which means the product will also be negative (odd number of negative signs results in a negative product).

3. -2 · -4: There are two negative numbers, so the product is positive (even number of negative signs results in a positive product).

4. 2 · -4 · 6 · -8 · 10: There are two negative numbers (-4, -8), so the product is positive (even number of negative signs results in a positive product).

Therefore, the expressions that have a negative value are -2 · 4 · -6 · 8 · -10 and 2 · -4 · -6 · -8 · -10. If you need to identify just one, the first expression is a valid answer.