Assume two numbers are a,b.
ATQ
a x b = 192....(i)
a - b = 4 ....(ii) { Square in both side}
(a - b)2 = 42
a2 + b2 -2ab = 16 {add 4ab both side}
a2 + b2 -2ab + 4ab = 16 + 4ab
a2 + b2 +2ab = 16 + 4x192
(a+b)2 = 784
a +b = 28
Hence the sum of the two numbers is 28.