Answer:
y = -2
Step-by-step explanation:
The line that is perpendicular to y-axis will be a horizontal line so it's slope is 0 => y = 0x + b or y = b
Using (5,-2) => -2 = b => b = -2
then y = -2
Assuming the speed is in miles per hour, simply divide the total distance by time.
515.97/6.5
The answer is 79.38 miles per hour