Its basically called null, it's not anything, nothing can be divided by 0, although 0 can be divided by anything. So the answer is that it's not a fraction.
I can't see the page it is glitches out try reopening it

Used:

Functions have the same derivatives if they differ a constant.
h(x) = f(x); g(x) = f(x) + const.
h'(x) = f'(x)
g'(x) = (f(x) + const.)' = f'(x) + (const.)' = f'(x) + 0 = f'(x)
h'(x) = g'(x)
Therefore yuor answer is A. f'(x)=g'(x)

Used:

Answer:
<h2>
12</h2>
Solution,
Summation FX= 5+10+6+12+X
=33+x
N(total no.of items)=5
Now,
Mean= summation FX/N
or 9=33+X/5
or 9*5=33+X ( cross multiplication)
or 45=33+X
or -x=33-45
or -x=-12
X=12
Hope this helps...
Good luck on your assignment..