How do I solve this?

Question

A plane flying the 3458-mi from New York City to London has a 50-MPH tailwind. The flight's point of no return is the point at which the flight time required to return to New York is the same as the time required to continue to London. If the Plane's speed in still air is 850 mph, how far is New York from the point of no return?

Answer 1

If the point is x miles from NYC, then since time = distance/speed,

(3458-x)/(850+50) = x/(850-50)

Answer 2

d = f(p-t) / 2p
now let's see the numbers
d = 3458(850-50) / 2(850)
d = 3458(800) / 1700
d = 2766400 / 1700
d = approx. 1627.29