Bird leaves its nest and travels 18 miles per hour downwind for x hours. on the return trip, the bird travels 3 miles per hour slower and has 5 miles left after x hours. what is the distance of the entire trip?

D = distance down wind
d - 6 = distance back
time = distance ÷ speed
x = d/20
x = (d - 6)/(16)

so d/20 = (d - 6)/16. Cross multiply
20d - 120 = 16d
-120 = -4d
30 = d so the whole trip assuming the bird gets back to the starting point is 60 miles