Question

A bird leaves its nest and travels 20 miles per hour downwind for x hours. On the return trip, the bird travels 4 miles per hour slower and has 6 miles left after x hours.

Answer 1

20x=16x+6
4x=6
x=1.5 hours

Answer 2

♥ Lets solve:
20x=16x+6
⇒Change into:
4x=6
⇒Then we get: 
x=1.5 hours