We need to find the value of X in each case.
The problem tells us to use the formula:

First, let's identify what each of the terms in the formula stands for. We have:

Now, we need to replace Z with the value given in each item, replace μ with 9 and replace σ with 2.
By doing so, we obtain:
A) Z = -0.5

B) Z = 0

C) Z = 1.96

Answer
A) X = 8
B) X = 9
C) X = 12.92