Given, two numbers differ by 4.

Let one of the numbers be ‘a’.

Second number = a – 4

Also, their product is 192.

⇒ a(a – 4) = 192

⇒ a² – 4a – 192 = 0

⇒ a² – 16a + 12a – 192 = 0

⇒ a(a – 16) + 12(a – 16) = 0

⇒ (a + 12)(a – 16) = 0

⇒ a = -12, 16

Thus numbers are -12, -16 or 12, 16