Question 1206363
.
<pre>

The problem does not say that all locations are along one straight line.


Therefore, based on common sense, we may assume that the locations are on the 2D 
Earth surface, which we may assume flat.


If so, then the problem is worded incorrectly.


In this case, the question should be posed about an inequality, not about an equation.


An inequality for the problem is  

      15 <= |H - K| <= 27  miles.


Here 15 = 21-6;  27 = 21 + 6.


It is the answer to question (A).


The answer to question (B) is  that Kayleigh can live from 15 to 27 miles from her school.
</pre>

Solved.



From reading this post, I see a fog in the head of the "math composer".


Also, I see that this "math composer" is not able to write Math problem in unambiguous mode.



At this forum, I see it every day and, to say more, several times per day.


But this so called "math composer" should not struggle of my words.
In the positive mode, it simply means that for him (or for her) there is a room to grow.