Find all solutions to the equation $6x^2 - 31x + 40 = 0.$ If you find more than one, then list the values separated by commas. If the solutions are not real, then they should be written in $a + bi$ form.

Apassenger train and a freight train leave san jose at 3pm, traveling in the same direction. the passenger train is going three times as fast as the freight train. at 6pm they are 240 miles apart. how fast is each travelling? explain your answer and show your