Question 1061144
.
Airplane A travels 2800 km at a certain speed.Plane B travels 2000 km at a speed 50 km/h faster than plane A in 3 hrs less time. 
find the speed of each plane?
~~~~~~~~~~~~~~~~~~~~


<pre>
Let "u" be the speed of the faster plane (plane B).
Then the speed of the plane A is (u-50) km/h.

The literal translation of the condition is this equation:

{{{2800/(u-50) - 2800/u}}} = 3.

Indeed, {{{2800/(u-50)}}} is the time for the plane A, while {{{2800/u}}} is the time for plane B.

To solve the equation, multiply both sides by u*(u-50). You will get

2800u - 2800(u-50) = 3u*(u-50),  or

3u^2 - 150u - 140000 = 0.

Solve this quadratic equation using the quadratic formula.
</pre>