Answer:
I think the answer is -1
Step-by-step explanation:
the sequence goes i, -i, 1, -1
Right? >_>
x=1
9 (5e - 3f)
45e -27f
45e = 9*5*e
27f = 9*3*f
The common factor is 9
9*5*e - 9*3*f