Answer:
y = - 2(x - 1)² + 18
Step-by-step explanation:
- 2x² + 4x + 16 ← factor out - 2 from the first 2 terms
= - 2(x² - 2x) + 16
using the method of completing the square
add/subtract ( half the coefficient of the x- term)² to x² - 2x
= - 2(x² + 2(- 1)x + 1 - 1) + 16
= - 2(x - 1)² + 2 + 16
= - 2(x - 1)² + 18 ← in vertex form
