Two trains on oppisite tracks leave the same station at the same time. One train travels at an average speed of 80 kilograms per hour and the other travels at an average speed of 70 kilograms per hour. How long after they leave the station will they be 50 km apart? PLS Help ASAP.

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Given that the points are: a(-4, 2), b(-2, 4), c(1, 3), and d(2, 2).  if polygon abcd rotates 90 counterclockwise to make a'b'c'd' will d is the question now be at the location (-2, 2); if polygon abcd rotates 180 clockwise to make a'b'c'd' the coordinate of a will become (3,-1). basically, a rotation of 90 degrees counterclockwise results in (x,y) becoming (-y,x).  (-4,2) becomes (-2,-4)(1,3) becomes (-3,1)(-2,1) becomes (-1,-2)(-3,-2) becomes (2,-3)