The denominator is 14-x.
Since the denominator cannot be equal to zero, you take the denominator, set it equal to zero, and solve.
This ill give you the value or values that must be eliminated (cannot be in the domain).
14 - x = 0
add x to both sides
14 = x
The domain is x ≠ 14
OR
(- ∞, 14) ∪ (14, ∞)
OR
All real numbers except 14