Question

A northbound train and a southbound train meet each other on parallel tracks heading in opposite directions. The northbound train travels 12 miles per hour faster than the southbound train. After 2.5 hours, they are 330 miles apart. At what speeds are the two trains traveling?

Answer 1

distance = speed * time

2.5(x+x+12) = 330
2x+12 = 132
2x=120
x=60

so, southbound speed is 60, northbound is 72

after 2.5 hours, the trains have traveled 150 and 180 miles, respectively.

Answer 2

A northbound train and a southbound train meet each other on parallel tracks heading in opposite directions. The northbound train travels 20 miles per hour faster than the southbound train. After 2.5 hours, they are 260 miles apart. At what speeds are the two trains traveling?

what is the equation using the information as it is given above that can be used to solve this problem ? using the variable
to represent the speed of the southbound train.