The distance between starting and ending point is 34 miles.
Step-by-step explanation:
Given,
Car moves 16 miles to north then 30 mile to east.
It forms a right angle triangle.
The straight line distance from starting to ending point represents hypotenuse.
To find the distance between starting and ending point.
Formula
By <em>Pythagoras theorem,</em>
h² = b²+l² where h is the hypotenuse, b is base and l is the another side.
Taking, b=16 and l=30 we get,
h² = 16²+30²
or, h = 
or, h =
= 34
Hence,
The distance between starting and ending point is 34 miles.
Here is the equation:

Since both decimals are negative, the answer will be positive.
- Negative times Negative = Positive
Divide both sides by -3.9 to leave the variable alone:

r is equal to 4 → r = 4