The distance between the trains is changing at the rate of (70 -60) = 10 mph. They will be in the same place (45 mi)/(10 mi/h) = 4.5 hours after they leave their respective cities. They will be 10 miles apart both 1 hour before that time and one hour after that time.
The trains will be 10 miles apart 3.5 hours after leaving.
They will be 10 miles apart the second time 5.5 hours after leaving.
R: (-inf, 0]
D: all real #'s
The correct answer is D (80,-30)
A square can be a rectangle but a rectangle can't be a square so seperate rectangles from triangles. since squares are special types of rectangles, they can go in the box of rectangles
