I need to add the following to my LP problem:

If the amount of workers hired in period $t$ ($H_t$) is higher than 25, the hiring cost is only 1 instead of 1.2.

Example: if 30 workers are hired in period $t$, the hiring cost is equal to $25\times1.2+5\times1=35$.

Example 2: if only 2 workers are hired in period $t$, the hiring cost is equal to 2.4.

How do I translate this to a **linear** equation?

Kind regards,

Bas