Factorise the following:

(x - 2)(x + 2) + 3

Using identity,

(a - b)(a + b) = (a² - b²).

(x - 2)(x + 2) + 3 = (x² - 4) + 3 = (x² - 1).

Using identity,

a² - b² = (a - b)(a + b).

(x² - 1) = (x - 1)(x + 1).

Hence, (x - 2)(x + 2) + 3 = (x - 1)(x + 1).