If your original equation was
, then a reflection over the x-axis means you need all the y-values to switch sign. This means you need to multiply that function by -1.
or 
Your answer would be -13 !!!
6.7 is closer to 7 so you would round it to 7
<h2>
Answer:</h2>
Option: B is the correct answer.
B. 36,623 feet
<h2>
Step-by-step explanation:</h2>
The angle of elevation is: 55 degree
We model this problem by taking a right angled triangle such that the side opposite to the 55 degree is of length 30000 feet.
Now let us consider x denote the distance of the plane from Francesa.
i.e. x denote the hypotenuse of the right angled triangle.
Hence, in right angled triangle i.e. ΔABC we have:

Round to the nearest feet we get: x=36,623 feet