Opinions because they are never wrong its just what you think not anyone else
Answer:

Step-by-step explanation:
Given


Required
Eliminate a
Multiply the first equation by -4

Add to the second equation

Solve brackets

Open bracket


At this point, a has been eliminated;
From the list of given options, the option that answers the question is 
23:8 is the simplest form. However, you can put 5.75:2 or even 2.86/1 if you are looking for the absolute simplest