Let x be the speed of the plane while still in the air and let y be the speed of the wind
so
x + y = 480mph ......(1)
x - y = 380mph ...... (2)
add both equations and solve for x
2x = 860 mph
x = 860/2=430mph = speed of the plane while stil in air
using equation .....(1)
430 + y =480 mph
y = 480 - 430 = 50 mph =speed of the wind