What does find the constant rate of change mean?

The change of the cost changes when the pounds of ham changes. When the pounds of ham is 0, it costs 0 dollars. When the pounds of ham is 3, it costs 12 dollars. The cost changes consistently with the pounds of ham. They change together. Every time the pounds of ham goes up by 3, the cost goes up by 12.

in simplified version   it would be x ≤-4

step-by-step explanation:

multiply each term in x ≤-4 by -1

i hope this is what you were looking for.

see attached graph