Answer:
y = (x + 5)² - 7
Explanation:
Given
y = x² + 10x + 18
To obtain vertex form use the method of completing the square
add/ subtract ( half the coefficient of the x- term )² to x² + 10x
y = x² + 2(5)x + 25 - 25 + 18
= (x + 5)² - 7 ← in vertex form