Why adding HBr to 2,4-hexadiene provides direct addition and conjugate addition products, while addition of HBr to 1,5-hexadiene provides only direct addition product?

the formula for the conversion of temperature from degree celsius to kelvin is:

the sample of water at is converted to kelvin temperature by using the above formula as:

on comparing the two samples of water at or we can say that at and at respectively. the difference between the temperatures of two samples of water is:

hence, one can say that the sample of water at is greater than the sample of water at by .