If P is a point in the x axis therefore this means that the y must be zero. Hence the coordinate of p is (x, 0).
We can use the distance formula to solve for the value of x:
d^2 = (x – x1)^2 + (y – y1)^2
13^2 = (x + 3)^2 + (0 – 5)^2
169 = (x + 3)^2 + 25
(x + 3)^2 = 144
x + 3 = ± 12
x = -15, 9
Hence P has two possible coordinates:
(-15, 0) and (9, 0)