Answer:
If they are travelling in opposite directions, their total distance is the 135. So add their distances together to get 135
x=Quinn's speed
x+5 = James' speed
they each travel for 5 hours
speed x time = distance
x(5) + (x+5)(5) = 135
Quinn's distance + James' distance = total distance
5x+5x+25=135
10x = 110
x = 11
Quinn travels at 11 mph and James travels at 16 mph
Quinn travels 55 miles (5x11)
and James travels 80 miles (16 x 5)
80 + 55=135