I think this is the answer, sorry I am not 100% sure
Divide the total distance traveled by the total time spent traveling. This will give you your average speed. S = 56.67 {\displaystyle S=56.67} . So if Ben traveled 50 mph for 3 hours, 60 mph for 2 hours, and 70 mph for 1 hour, his average speed was about 57 mph.
A, B, and D are the correct answers.
The answer is 0 is this if i stands for a square root.
The answer is -81 if i is a variable.