Answer:
Jamal's inequality is correct
Step-by-step explanation:
Given

Gary: 
Nancy: 
Jamal: 
Required
Which of the inequalities is/are true
Gary: 

Divide both sides by 0.5


Rewrite as:

Gary's inequality is false because: 
Nancy: 

Collect like terms


Divide both sides by -1

Nancy's inequality is incorrect because: 0,1,3,4 and 6 are less than 12
Jamal: 



Rewrite as:

Jamal's inequality is correct because: 0,1,3,4,6 and 12 