If a plane can travel 480 miles per hour with the wind and 440 mph against the wind, find the speed of the plane without a wind and the speed of the wind.

Solution:

the speed of the plane without a wind: x

 the speed of the wind:y

so

x + y = 480

x - y = 440

x = 460

y =20

SO

the speed of the plane without a wind: 460 mph

the speed of the wind: 20 mph