Answer:
Jet speed = 395
Wind = 7
Step-by-step explanation:
Let :
Speed of jet = x
Speed of wind = y
Distance = speed * time
With tailwind :
804 = (jet speed + wind speed) * time
804 = (x + y) * 2
804/2 = (x + y) * 2/2
x + y = 402 - - - (1)
Into a headwind :
776 = (jet speed - wind speed) * time
776 = (x - y) * 2
776/2 = (x - y) * 2/2
x - y = 388 - - - (2)
From (1)
x = 402 - y
Put x = 402 - y in (2)
402 - y - y = 388
402 - 2y = 388
-2y = 388 - 402
-2y = - 14
y = 7
x = 402 - y
x = 402 - 7
x = 395