Question 527439
Let
P = plane speed
T = Tail wind speed

When travelling from Atlant,Georgia to San Francisco,California,it takes 5.6 hours to cover distance which is more than return leg meaning tail wind is acting in opposite direction.
Therefore effective speed = P-T

So 5.6= 2100/(P-T)....................................(1)

Further, travel from San Francisco to Atlanta takes less time so effective speed is P+T 
So 4.8 = 2100/(P+T)....................................(2)

Solving eq 1 & 2 results in
P = 406.25 mph and T = 31.25 mph