Find the common factors of the given term.
12x, 36
∵                                      12x = 2 × 2 × 3 × x = (2 × 2 × 3) × x
and                                   36 = 2 × 2 × 3 × 3 = (2 × 2 × 3) × 3
∴         the common factor = 2 × 2 × 3
                                         = 12