Answer:
x = - 4
Step-by-step explanation:
Given
- x² - 8x - 16 = 0 ( multiply through by - 1 to clear the leading negative )
x² + 8x + 16 = 0 ← this is a perfect square
(x + 4)² = 0 ( take the square root of both sides )
x + 4 = 0 ( subtract 4 from both sides )
x = - 4
