Final answer:
The values of x that satisfy the equation x² - 9 = 0 are -3 and 3.
Step-by-step explanation:
The equation x² - 9 = 0 can be rewritten as (x + 3)(x - 3) = 0 by factoring the quadratic expression. This means that either (x + 3) = 0 or (x - 3) = 0. Solving for x in each equation, we find that x = -3 or x = 3. So, the values of x that satisfy the equation are -3 and 3.