The length is going to be 15.5. Please message me if you want the explanation
Answer:
19 > DB > 5
Step-by-step explanation:
In a triangle Δ ABC, AC = 7, and BC = 18.
Therefore, the length of the third side of the triangle Δ ABC i.e. length of AB can have a maximum value of < (7 + 18) i.e. 25 and the minimum value of the length AB will be > (18 - 7) i.e. 11
Hence, the length of AB will be given by 25 > AB > 11.
Now, AB = AD + DB = 6 + DB {Since length of AD is given to be 6}
Therefore, 25 > 6 + DB > 11
⇒ 19 > DB > 5 (Answer)
For this case we must find a linear equation of the form:

Where,
m: slope of the line
b: cutting point with vertical axis.
For the slope we have the following equation:

Substituting values we have:

We observe that the slope of the line is not defined.
Therefore, the line is vertical.
Thus, the equation of the line is given by:

Answer:
The equation of the line is given by:

17.89, is this an option?