Answer: R = 58.3 miles
Step-by-step explanation:
Displacement is a vector quantity. That is, it has both magnitude and direction.
As Elizabeth drove 30 miles to the south, then drove 50 miles to the east. The resultant displacement can be achieved by using pythagorean theorem
R^2 = 30^2 + 50^2
R^2 = 900 + 2500
R^2 = 3400
R = sqrt(3400)
R = 58.3 miles
The vector diagram that shows her resultant displacement is attached as a file.