The given equation is:

$(x + 3)^2 - 15 = 0$

Solution:

1. Isolate the squared term
   $(x + 3)^2 = 15$

2. Take the square root on both sides
   $x + 3 = \pm\sqrt{15}$

3. Solve for $x$
   $x = -3 \pm \sqrt{15}$

Final Answer:

$x = -3 + \sqrt{15}, \quad x = -3 - \sqrt{15}$

Would you like a step-by-step explanation in more detail?

Related Questions:

1. How do you solve quadratic equations using the square root method?
2. What is the approximate decimal value of $\sqrt{15}$?
3. How do you check if your solutions are correct?
4. What other methods can be used to solve quadratic equations?
5. What are the real-world applications of solving quadratic equations?

Tip:

When solving equations with squares, always consider both the positive and negative square roots!