.
On jet stream see this Wikipedia article: https://en.wikipedia.org/wiki/Jet_stream
u - v = (1) ("A jet travels 1102 mi against a jetstream in 2 hours")
v + v = (2) ("and 1262 mi with the jetstream in the same amount of time.")
Or
u - v = 551,
u + v = 631.
----------------Add
2u = 1182, u = = 591 mi/h is the rate of the jet plane in still air.
Then v = 631 - 591 = 40 mi/h is the rate of the jetstream.
It is a typical "tailwind and headwind" word problem.
See the lessons
- Wind and Current problems
- Wind and Current problems solvable by quadratic equations
- Selected problems from the archive on a plane flying with and against the wind
in this site.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this textbook under the section "Word problems", the topic "Travel and Distance problems".