No they are not equivalent and if you are trying to get a mixed number try dividing
The sequence is geometric, so

for some constant r. From this rule, it follows that

and we can determine the first term to be

Now, by substitution we have

and so on down to (D)

(notice how the exponent on r and the subscript on a add up to n)
Answer: 9 and 12
Step-by-step explanation:
Find the pattern
z,Y,x,W,v,U
The letter from the end of the alphabet are skipped every letter
a,B,c,D,e,F
The pattern is the same as the end of the alphabet
Therefore, the next letter would be S as we have to skip one from U, this being T.
You can use a calculator for this if your teacher lets you to make it easier