Question 1056202
speed*time=distance
The distance the plane is from NY is 970 mph*time in hours, going east

At any given point, the time required to go to London is distance/speed
The time required to go back to NY is distance/speed
To London, we will call the distance x
To New York, we will call the distance 3458-x
speed to London is 970 mph
speed to New York is 830 mph
Time to London is x/970
Time to NY is (3458-x)/830
They are equal.
(3458-x)/830=x/970
Cross-multiply
3354260-970x=830x
1800x=3354260
x=1863.48 miles
The distance to New York requires an extra step since I didn't make the distance x.
1594.52 miles ANSWER
at 970 mph, 1863.48 miles is 1.921 hours
at 830 mph 1594.52 miles is 1.921 hours