Answer:
x = 5, x = 7
Step-by-step explanation:
to find the zeros let f(x) = 0 , that is
x² - 12x + 35 = 0 ( subtract 35 from both sides )
x² - 12x = - 35
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(- 6)x + 36 = - 35 + 36
(x - 6)² = 1 ( take the square root of both sides )
x - 6 = ± [tex]\sqrt{1}[/tex] = ± 1 ( add 6 to both sides )
x = 6 ± 1
then
x = 6 - 1 = 5
x = 6 + 1 = 7