Let's evaluate the given expression step by step:

The expression is:

$-\sqrt{25} - \sqrt{45} + \sqrt{125}$

Step 1: Evaluate each square root

1. $\sqrt{25} = 5$
2. Simplify $\sqrt{45}$:
   $\sqrt{45} = \sqrt{9 \cdot 5} = \sqrt{9} \cdot \sqrt{5} = 3\sqrt{5}$
3. Simplify $\sqrt{125}$:
   $\sqrt{125} = \sqrt{25 \cdot 5} = \sqrt{25} \cdot \sqrt{5} = 5\sqrt{5}$

Step 2: Substitute these values into the expression

$-\sqrt{25} - \sqrt{45} + \sqrt{125} = -5 - 3\sqrt{5} + 5\sqrt{5}$

Step 3: Combine like terms

1. Combine $-3\sqrt{5} + 5\sqrt{5}$:
   $-3\sqrt{5} + 5\sqrt{5} = 2\sqrt{5}$
2. Add the constant term: $-5 + 2\sqrt{5}$

Final Answer:

$-5 + 2\sqrt{5}$

This is the simplified form of the expression.

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Would you like a breakdown of the simplification steps or additional clarification?

Here are 5 related questions to practice:

1. Simplify $\sqrt{72} + \sqrt{50}$.
2. Evaluate $-\sqrt{16} + \sqrt{81} - \sqrt{64}$.
3. Simplify $3\sqrt{45} - 2\sqrt{20} + 4\sqrt{5}$.
4. Rationalize the denominator of $\frac{1}{\sqrt{2}}$.
5. Expand and simplify $(2\sqrt{3} + 5)^2$.

Tip: Always look for perfect squares within a radical to simplify square roots easily.