h is for time difference
SPEEDS TIMES DISTANCE
WITH WIND r+w d/(r+w) d
AGAINST WIND r-w d/(r-w) d
DIFFERENCE h
Solve for w.
Using general solution for quadratic equation, and not assuming the quadratic would be factorable,
-------the PLUS form will probably be what you want. Substitute the given values now and evaluate both solutions for w, and decide which makes sense.
Substitute the given values into the formula for w, and should find .