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
