Answer:
x = 6, x = - 6
Step-by-step explanation:
Given
y = x² - 36
To find the zeros let y = 0, that is
x² - 36 = 0 ← x² - 36 is a difference of squares and factors in general as
a² - b² = (a - b)(a + b), thus
x² - 36 = 0
x² - 6² = 0
(x - 6)(x + 6) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 6 = 0 ⇒ x = 6
x + 6 = 0 ⇒ x = - 6
