The given expression is:

$7\sqrt{7} + 2\sqrt{7} - 5\sqrt{7} - 3$

Let's simplify this step-by-step:

1. Combine like terms involving $\sqrt{7}$: $(7 + 2 - 5)\sqrt{7}$ Simplify the coefficients: $4\sqrt{7}$

2. Now include the $-3$: $4\sqrt{7} - 3$

So, the simplified answer is:

$4\sqrt{7} - 3$

Would you like further clarification or details on this process?

5 Related Questions:

1. How do you combine like terms involving radicals?
2. What happens if there were more different radicals in the expression?
3. Can you explain how to add or subtract expressions with different radicals?
4. What is the process to rationalize an expression involving radicals?
5. How do you simplify a more complex radical expression with multiple terms?

Tip: Always combine like terms when simplifying expressions, even if they include radicals.