Answer:
y (plane speed) 400 miles/hr
x (wind speed)  40 miles/hr
Step-by-step explanation:
going into the wind make the plane flew 5,5 hours to get 1980 miles, implies the real travel speed was
1980 / 5,5 = 360 miles/hours, and at the same time is the result of:  
 speed plane (y)  in direction A to B  plus wind speed (x) in direction B to A. Notice opposites direction speed, so we have:
y + (-x) = 360          (1)
The return fly  took 4,5 hours so 1980/4,5 = 440 miles/ hours as the result 
Y + x = 440             (2)
We have a two equation with two variables system, It could be solved for any of the procedures. We will use the substitution method.
From equation      (1)        y + (-x) = 360         y  - x = 360      y = 360 + x    (1)
In the second equation    
y + x = 440         then we replace y for its value as function of x
(360 + x ) + x = 440
Solving for x        360 + 2x = 440      or    2x = 440 – 360        
  x   (440 - 360)/2
  x = 40 miles/hr
  X (wind speed ) = 40 miles/hr
And replacing the value of x in eq. (1)        y = 360 + 40 = 400
 Y (plane speed) = 400 miles /hr