Answer:
F and D
Step-by-step explanation:
When a negative number is multiplied by a positive number, the result is a negative number. When a negative number is multiplied by another negative number, the result is positive.
To solve this problem you must apply the proccedure shown below:
1. Clear the radius from the formula for the circumference of a circle and substitute values, as following:

2. Substitute the radius calculated into the formula for calculate the surface area of the sphere:

The answer is: 
School to mall - 16 miles
mall to library - 30 miles
16²+30²=X²
256+900=X²
X²=1156
X=34
16+30=46
hypotenuse = 34
46-34=12
So Mike travel 12 miles more.