Question

Which zero pair could be added to the function so that the function can be written in vertex form?

Answer 1

The function in this problem should be: f(x) =x² + 12x + 6 

y = x² + 12x + 6
y - 6 = x² + 12x 

x² ⇒ x * x
12x ⇒ 2*6*x
missing number is 6² = 36 

y - 6 + 36 = x² + 12x + 36

(x+6)(x+6) ⇒ x(x+6)+6(x+6) ⇒ x² + 6x + 6x + 36 = x² + 12x + 36

y + 30 = x² + 12x + 36
y = (x+6)² - 30

Choice is D. 36,-36