Answer: A is (arithmetic sequence)
and D is 1 2 3 4 5 6 7
Unfortunately, I only know the answer to those two.
Sorry.
2f +4f +2 -3
combine the like terms to get 6f-1
so yes they are equivalent
2f+4f+2-3 at f=3 would also be 17
X=1. Chose C. Hoped that will help