An airplane takes 3 hours to travel a distance of 2160 miles with wind. the return trip takes 4 hours against the wind. Find the speed of the airplane in still air and the speed of the wind.

We have 2 situation one with wind and one against wind

Speed = x , W= Wind

***case 1 ( With Wind) *case 2 ( Against Wind)**

t=3 hr d= 2160 m. Rate = x + W t=4 hr d= 2160 m. Rate = x - W

**Distance = Rate * Time**

2160 = (x+W) * 3 ** ** 2160 = (x-W) * 4

2160 / 3 = (x+W) 2160/4 = x-W

720 = x+W 540 = x-W

NOW 2 equations solve by substitution or elimination. ( i did Elimination)

720 = x+W

540 = x-W

---------------------

1260 = 2x (W was eliminated) solve for x

**x = 630 Speed of the Airplane **

now solve for W. **W = 90 Speed of the Wind**