Let x and (442-x) represent the distance of the trains traveled. X/90 mph=442-x/80 mph
Cross multiply 80×x =90(442-x)
80x=90×442-90x
170x=90×442
X= 90×442/170
X=234, distance traveled by train going 90mph
234mi/90mph = 2.6 hr, time it takes for the two trains tok meet.
Checking your answer:
90×2.6+80×2.6=234mi+208mi = 442mi