Assume the two planes are heading 'towards P'. For now, let's not get too wound up about the x and y aspects. We'll always 'know' the two places are at right angles to each other.
First let's create two equations that represent the 'location' of each plane.
Plane1Location = 150 - 450(t)
To find the equation for the location of Plane 1, we start by assuming that Plane 1 is initially located at a distance of 150 units from point P. We then subtract the product of the speed at which Plane 1 is moving (450 units per unit of time) and the time elapsed (t) from the initial distance of 150. This gives us the equation:
Plane1Location = 150 - 450(t)
Similarly, we can create the equation for the location of Plane 2. Let's assume that Plane 2 is initially located at a distance of 100 units from point P. We will also need to know the speed at which Plane 2 is moving. Let's say Plane 2 is moving at a speed of 350 units per unit of time. Therefore, the equation for the location of Plane 2 would be:
Plane2Location = 100 - 350(t)
These equations represent the location of each plane as a function of time (t), assuming they are moving towards point P at right angles to each other.