a pilot is testing a new experimental craft . the cruising speed is classified information. in a test the jet traveled 6,000 miles. the pilot reveled that if he had increased his speed 300 mph the total trip would have taken one hour less. Determine the cruising speed of the jet.

Let x be the cruising speed of the jet (in mph). Then the flight took 6000/x hours. If the speed were increased by 300 mph, the flight would have taken 6000/(x+300) hours or 1 hour less.

We get an equation: 6000/x - 6000(x+300) = 1

Multiply both parts by x(x+300): 6000*(x+300) - 6000*x = x^2 + 300x

We have a quadratic equation x^2 + 300 x - 1800000 = 0 with two solutions: