In factorization, we write the middle term of the quadratic equation either as a sum of two numbers or difference of two numbers such that the equation can be factorized.

⇒ x² – 3x – 1 = 3x – 9

⇒ x² – 6x + 8 = 0

⇒ x² – 4x – 2x + 8 = 0

⇒ x(x – 4) – 2(x – 4) = 0

⇒ (x – 2)(x – 4) = 0

⇒ x = 2, 4