Simplify the Expression: x² + (-9) Step by Step

To solve the given equation $x^2 - 9 = 0$, we will utilize the difference of squares technique.

The equation can be written as:

$x^2 - 3^2 = 0$

Recognizing this as a difference of squares, we have:

$(x - 3)(x + 3) = 0$

This implies that either $x - 3 = 0$ or $x + 3 = 0$.

Solving these two linear equations will give us the values of $x$.

• For $x - 3 = 0$, adding 3 to both sides gives:

$x = 3$.

• For $x + 3 = 0$, subtracting 3 from both sides gives:

$x = -3$.

Therefore, the solutions to the equation $x^2 - 9 = 0$ are $x = 3$ and $x = -3$.

Conclusively, we have:

The solution to the problem is $\mathbf{x = \pm 3}$.