PLEASE HELP
will be giving brianlist

Terrell drove to the mountains at an average
of 40 miles per hour. His return trip, by the
same roads, averaged 50 miles per hour. His
total driving time was 9 hours. How far did
he drive one way?

We can have two d = rt equations.

d = 40 t

d = 50 (9 - t)

We know the distance is the same, so we can just set the equations equal to each now.

40 t = 50 (9 - t)

40 t = 450 - 50 t

90 t = 450

t = 5

So, Terrell took 5 hours going 40 mph, and 4 hours going 50 mph. 5 * 40 gives us 200 miles one way.