Two Planes leave the same airpot at 1100 am traveling in opp

Two Planes leave the same airpot at 11:00 a.m., traveling in opposite directions. One of the planes travels at a speed that is 150 mi/h faster than the other. At 1:00 p.m., the lanes are 1900 miles apart. Find the speed of the faster plane.

Solution

Let the speed of the slower plane be x. The faster planes speed must be x+150.
Their combined speed is 2x + 150 miles per hour.
In two hours they travel 2(2x +150) miles
so 2(2x + 150)= 1900
2(2x + 150)= 1900
4x + 300 = 1900
4x = 1600
x=400
so the faster plane is travelling at 400+150=550 miles per hour.